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Kojima T, Masuda S. Construction of the Rhodobacter sphaeroides strain overproducing 5-aminolevulinic acid by insertion of endogenous promoter. J GEN APPL MICROBIOL 2024; 69:270-277. [PMID: 37482422 DOI: 10.2323/jgam.2023.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
5-Aminolevulinic acid (ALA) is a precursor of heme and a natural amino acid synthesized in the cells of most living organisms. Currently, ALA is used as an ingredient in pharmaceuticals, supplements, cosmetics, feed, fertilizers, and other products. ALA is mainly produced by industrial fermentation by the photosynthetic bacterium Rhodobacter sphaeroides. In this study, we tried to improve the ALA productivity by R. sphaeroides using a genetic strategy to highly express ALA synthase (ALAS) genes. We inserted a constitutive promoter (PrrnB or Prsp_7571) upstream of genes encoding ALAS (hemA and/or hemT) to construct strains that constitutively express ALAS. The highest transcript levels of hemA were observed in the strain where PrrnB was inserted into the hemA promoter region and were 3.5-fold higher than those in the wild-type. The highest transcript levels of hemT were observed in the strain where PrrnB was inserted into the hemT promoter region and were 46-fold higher than those in the wild-type. The maximum ALAS activity was observed in crude cell extracts of the strain where PrrnB was inserted into the hemT promoter region under optimized growth conditions that was 2.7-fold higher than that in the wild type. This strain showed 12-fold accumulation of ALA compared to the wild-type. Thus, we improved ALA productivity without using exogenous DNA sequences. In the future, further improvement in ALA productivity may be expected by applying this approach to current industrial ALA-producing bacteria.
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Affiliation(s)
- Takuma Kojima
- Fermentation Research Center, Neopharma Japan Co., Ltd
- Department of Life Science and Technology, Tokyo Institute of Technology
| | - Shinji Masuda
- Department of Life Science and Technology, Tokyo Institute of Technology
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2
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Lee S, Kim YH, Min J. The potential of Rhodobacter sphaeroides extract as an alternative supplement for cell culture systems. Microbiol Spectr 2024; 12:e0245623. [PMID: 38319116 PMCID: PMC10913442 DOI: 10.1128/spectrum.02456-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 01/12/2024] [Indexed: 02/07/2024] Open
Abstract
It is essential to identify suitable supplements that enhance cell growth, viability, and functional development in cell culture systems. The use of fetal bovine serum (FBS) has been common, but it has limitations, such as batch-to-batch variability, ethical concerns, and risks of environmental contamination. In this study, we explore the potential of Rhodobacter sphaeroides extract, derived from a probiotic photosynthetic bacterium, as an alternative supplement. Our results demonstrate that the extract from R. sphaeroides significantly improves various aspects of cell behavior compared to serum-free conditions. It enhances cell growth and viability to a greater extent than FBS supplementation. Additionally, the extract alleviates oxidative stress by reducing intracellular levels of reactive oxygen species and stimulates lysosomal activity, contributing to cellular processes. The presence of abundant amino acids, glycine and arginine, in the extract may play a role in promoting cell growth. These findings emphasize the potential of R. sphaeroides extract as a valuable supplement for cell culture, offering advantages over the use of FBS.IMPORTANCEThe choice of supplements for cell culture is crucial in biomedical research, but the widely used fetal bovine serum (FBS) has limitations in terms of variability, ethics, and environmental risks. This study explores the potential of an extract from Rhodobacter sphaeroides, a probiotic bacterium, as an alternative supplement. The findings reveal that the R. sphaeroides extract surpasses FBS in enhancing cell growth, viability, and functionality. It also mitigates oxidative stress and stimulates lysosomal activity, critical for cellular health. The extract's abundance of glycine and arginine, amino acids with known growth-promoting effects, further highlights its potential. By providing a viable substitute for FBS, the R. sphaeroides extract addresses the need for consistent, ethical, and environmentally friendly cell culture supplements. This research paves the way for sustainable and reliable cell culture systems, revolutionizing biomedical research and applications in drug development and regenerative medicine.
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Affiliation(s)
- Subin Lee
- Department of Bioprocess Engineering, Jeonbuk National University, Jeonju, Jeonbuk, South Korea
| | - Yang-Hoon Kim
- School of Biological Sciences, Chungbuk National University, Cheongju, South Korea
| | - Jiho Min
- Department of Bioprocess Engineering, Jeonbuk National University, Jeonju, Jeonbuk, South Korea
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3
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Kis M, Szabó T, Tandori J, Maróti P. Roadmap of electrons from donor side to the reaction center of photosynthetic purple bacteria with mutated cytochromes. Photosynth Res 2024; 159:261-272. [PMID: 38032488 PMCID: PMC10991045 DOI: 10.1007/s11120-023-01059-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 10/28/2023] [Indexed: 12/01/2023]
Abstract
In photosynthetic bacteria, the absorbed light drives the canonical cyclic electron transfer between the reaction center and the cytochrome bc1 complexes via the pools of mobile electron carriers. If kinetic or structural barriers hinder the participation of the bc1 complex in the cyclic flow of electrons, then the pools of mobile redox agents must supply the electrons for the multiple turnovers of the reaction center. These conditions were achieved by continuous high light excitation of intact cells of bacterial strains Rba. sphaeroides and Rvx. gelatinosus with depleted donor side cytochromes c2 (cycA) and tetraheme cytochrome subunit (pufC), respectively. The gradual oxidation by ferricyanide further reduced the availability of electron donors to pufC. Electron transfer through the reaction center was tracked by absorption change and by induction and relaxation of the fluorescence of the bacteriochlorophyll dimer. The rate constants of the electron transfer (~ 3 × 103 s‒1) from the mobile donors of Rvx. gelatinosus bound either to the RC (pufC) or to the tetraheme subunit (wild type) were similar. The electrons transferred through the reaction center dimer were supplied entirely by the donor pool; their number amounted to about 5 in wild type Rvx. gelatinosus and decreased to 1 in pufC oxidized by ferricyanide. Fluorescence yield was measured as a function of the oxidized fraction of the dimer and its complex shape reveals the contribution of two competing processes: the migration of the excitation energy among the photosynthetic units and the availability of electron donors to the oxidized dimer. The experimental results were simulated and rationalized by a simple kinetic model of the two-electron cycling of the acceptor side combined with aperiodic one-electron redox function of the donor side.
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Affiliation(s)
- M Kis
- Balaton Limnological Research Institute, Klebelsberg K. Utca 3, Tihany, 8237, Hungary
| | - T Szabó
- Institute of Medical Physics, University of Szeged, Korányi Fasor 9, Szeged, 6720, Hungary
| | - J Tandori
- Institute of Medical Physics, University of Szeged, Korányi Fasor 9, Szeged, 6720, Hungary
| | - P Maróti
- Institute of Medical Physics, University of Szeged, Korányi Fasor 9, Szeged, 6720, Hungary.
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4
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Huang X, Vasilev C, Swainsbury D, Hunter C. Excitation energy transfer in proteoliposomes reconstituted with LH2 and RC-LH1 complexes from Rhodobacter sphaeroides. Biosci Rep 2024; 44:BSR20231302. [PMID: 38227291 PMCID: PMC10876425 DOI: 10.1042/bsr20231302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/30/2023] [Accepted: 01/16/2024] [Indexed: 01/17/2024] Open
Abstract
Light-harvesting 2 (LH2) and reaction-centre light-harvesting 1 (RC-LH1) complexes purified from the photosynthetic bacterium Rhodobacter (Rba.) sphaeroides were reconstituted into proteoliposomes either separately, or together at three different LH2:RC-LH1 ratios, for excitation energy transfer studies. Atomic force microscopy (AFM) was used to investigate the distribution and association of the complexes within the proteoliposome membranes. Absorption and fluorescence emission spectra were similar for LH2 complexes in detergent and liposomes, indicating that reconstitution retains the structural and optical properties of the LH2 complexes. Analysis of fluorescence emission shows that when LH2 forms an extensive series of contacts with other such complexes, fluorescence is quenched by 52.6 ± 1.4%. In mixed proteoliposomes, specific excitation of carotenoids in LH2 donor complexes resulted in emission of fluorescence from acceptor RC-LH1 complexes engineered to assemble with no carotenoids. Extents of energy transfer were measured by fluorescence lifetime microscopy; the 0.72 ± 0.08 ns lifetime in LH2-only membranes decreases to 0.43 ± 0.04 ns with a ratio of 2:1 LH2 to RC-LH1, and to 0.35 ± 0.05 ns for a 1:1 ratio, corresponding to energy transfer efficiencies of 40 ± 14% and 51 ± 18%, respectively. No further improvement is seen with a 0.5:1 LH2 to RC-LH1 ratio. Thus, LH2 and RC-LH1 complexes perform their light harvesting and energy transfer roles when reconstituted into proteoliposomes, providing a way to integrate native, non-native, engineered and de novo designed light-harvesting complexes into functional photosynthetic systems.
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Affiliation(s)
- Xia Huang
- Department of Biological Sciences, Xi’an Jiaotong-Liverpool University, Suzhou, Jiangsu 215123, China
- Jinan Guoke Medical Technology Development Co., Ltd, Jinan, Shandong 250101, China
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - Cvetelin Vasilev
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - David J.K. Swainsbury
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, U.K
| | - C. Neil Hunter
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
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5
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Börner J, Friedrich T, Klug G. RNase III participates in control of quorum sensing, pigmentation and oxidative stress resistance in Rhodobacter sphaeroides. Mol Microbiol 2023; 120:874-892. [PMID: 37823424 DOI: 10.1111/mmi.15181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/21/2023] [Accepted: 09/26/2023] [Indexed: 10/13/2023]
Abstract
RNase III is a dsRNA-specific endoribonuclease, highly conserved in bacteria and eukarya. In this study, we analysed the effects of inactivation of RNase III on the transcriptome and the phenotype of the facultative phototrophic α-proteobacterium Rhodobacter sphaeroides. RNA-seq revealed an unexpectedly high amount of genes with increased expression located directly downstream to the rRNA operons. Chromosomal insertion of additional transcription terminators restored wild type-like expression of the downstream genes, indicating that RNase III may modulate the rRNA transcription termination in R. sphaeroides. Furthermore, we identified RNase III as a major regulator of quorum-sensing autoinducer synthesis in R. sphaeroides. It negatively controls the expression of the autoinducer synthase CerI by reducing cerI mRNA stability. In addition, RNase III inactivation caused altered resistance against oxidative stress and impaired formation of photosynthetically active pigment-protein complexes. We also observed an increase in the CcsR small RNAs that were previously shown to promote resistance to oxidative stress. Taken together, our data present interesting insights into RNase III-mediated regulation and expand the knowledge on the function of this important enzyme in bacteria.
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Affiliation(s)
- Janek Börner
- Institute of Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Tobias Friedrich
- Biomedical Informatics and Systems Medicine, Justus-Liebig-University Giessen, Giessen, Germany
- Institute of Biochemistry, Justus-Liebig-University Giessen, Giessen, Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Giessen, Germany
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6
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Satoh I, Gotou K, Nagatsuma S, Nagashima KVP, Kobayashi M, Yu LJ, Madigan MT, Kimura Y, Wang-Otomo ZY. Selective expression of light-harvesting complexes alters phospholipid composition in the intracytoplasmic membrane and core complex of purple phototrophic bacteria. Biochim Biophys Acta Bioenerg 2023; 1864:149001. [PMID: 37527691 DOI: 10.1016/j.bbabio.2023.149001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/23/2023] [Accepted: 07/26/2023] [Indexed: 08/03/2023]
Abstract
Phospholipid-protein interactions play important roles in regulating the function and morphology of photosynthetic membranes in purple phototrophic bacteria. Here, we characterize the phospholipid composition of intracytoplasmic membrane (ICM) from Rhodobacter (Rba.) sphaeroides that has been genetically altered to selectively express light-harvesting (LH) complexes. In the mutant strain (DP2) that lacks a peripheral light-harvesting (LH2) complex, the phospholipid composition was significantly different from that of the wild-type strain; strain DP2 showed a marked decrease in phosphatidylglycerol (PG) and large increases in cardiolipin (CL) and phosphatidylcholine (PC) indicating preferential interactions between the complexes and specific phospholipids. Substitution of the core light-harvesting (LH1) complex of Rba. sphaeroides strain DP2 with that from the purple sulfur bacterium Thermochromatium tepidum further altered the phospholipid composition, with substantial increases in PG and PE and decreases in CL and PC, indicating that the phospholipids incorporated into the ICM depend on the nature of the LH1 complex expressed. Purified LH1-reaction center core complexes (LH1-RC) from the selectively expressing strains also contained different phospholipid compositions than did core complexes from their corresponding wild-type strains, suggesting different patterns of phospholipid association between the selectively expressed LH1-RC complexes and those purified from native strains. Effects of carotenoids on the phospholipid composition were also investigated using carotenoid-suppressed cells and carotenoid-deficient species. The findings are discussed in relation to ICM morphology and specific LH complex-phospholipid interactions.
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Affiliation(s)
- I Satoh
- Faculty of Science, Ibaraki University, Mito 310-8512, Japan
| | - K Gotou
- Faculty of Science, Ibaraki University, Mito 310-8512, Japan
| | - S Nagatsuma
- Faculty of Science, Ibaraki University, Mito 310-8512, Japan
| | - K V P Nagashima
- Research Institute for Integrated Science, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama, Kanagawa 221-8686, Japan
| | - M Kobayashi
- National Institute of Technology, Ariake College, Omuta, Fukuoka 836-8585, Japan
| | - L-J Yu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - M T Madigan
- School of Biological Sciences, Department of Microbiology, Southern Illinois University, Carbondale, IL 62901, USA
| | - Y Kimura
- Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Nada, Kobe 657-8501, Japan
| | - Z-Y Wang-Otomo
- Faculty of Science, Ibaraki University, Mito 310-8512, Japan.
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7
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Vitukhnovskaya LA, Zaspa AA, Mamedov MD. Generation of Electric Potential Difference by Chromatophores from Photosynthetic Bacteria in the Presence of Trehalose under Continuous Illumination. Biochemistry (Mosc) 2023; 88:1428-1437. [PMID: 38105015 DOI: 10.1134/s0006297923100024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/20/2023] [Accepted: 08/26/2023] [Indexed: 12/19/2023]
Abstract
Measurement of electrical potential difference (Δψ) in membrane vesicles (chromatophores) from the purple bacterium Rhodobacter sphaeroides associated with the surface of a nitrocellulose membrane filter (MF) impregnated with a phospholipid solution in decane or immersed into it in the presence of exogenous mediators and disaccharide trehalose demonstrated an increase in the amplitude and stabilization of the signal under continuous illumination. The mediators were the ascorbate/N,N,N'N'-tetramethyl-p-phenylenediamine pair and ubiquinone-0 (electron donor and acceptor, respectively). Although stabilization of photoelectric responses upon long-term continuous illumination was observed for both variants of chromatophore immobilization, only the samples immersed into the MF retained the functional activity of reaction centers (RCs) for a month when stored in the dark at room temperature, which might be due to the preservation of integrity of chromatophore proteins inside the MF pores. The stabilizing effect of the bioprotector trehalose could be related to its effect on both the RC proteins and the phospholipid bilayer membrane. The results obtained will expand current ideas on the use of semi-synthetic structures based on various intact photosynthetic systems capable of converting solar energy into its electrochemical form.
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Affiliation(s)
- Liya A Vitukhnovskaya
- Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, 119992, Russia
- Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Andrei A Zaspa
- Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, 119992, Russia
| | - Mahir D Mamedov
- Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, 119992, Russia.
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8
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Lakey BD, Alberge F, Parrell D, Wright ER, Noguera DR, Donohue TJ. The role of CenKR in the coordination of Rhodobacter sphaeroides cell elongation and division. mBio 2023; 14:e0063123. [PMID: 37283520 PMCID: PMC10470753 DOI: 10.1128/mbio.00631-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 06/08/2023] Open
Abstract
Cell elongation and division are essential aspects of the bacterial life cycle that must be coordinated for viability and replication. The impact of misregulation of these processes is not well understood as these systems are often not amenable to traditional genetic manipulation. Recently, we reported on the CenKR two-component system (TCS) in the Gram-negative bacterium Rhodobacter sphaeroides that is genetically tractable, widely conserved in α-proteobacteria, and directly regulates the expression of components crucial for cell elongation and division, including genes encoding subunit of the Tol-Pal complex. In this work, we show that overexpression of cenK results in cell filamentation and chaining. Using cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET), we generated high-resolution two-dimensional (2D) images and three-dimensional (3D) volumes of the cell envelope and division septum of wild-type cells and a cenK overexpression strain finding that these morphological changes stem from defects in outer membrane (OM) and peptidoglycan (PG) constriction. By monitoring the localization of Pal, PG biosynthesis, and the bacterial cytoskeletal proteins MreB and FtsZ, we developed a model for how increased CenKR activity leads to changes in cell elongation and division. This model predicts that increased CenKR activity decreases the mobility of Pal, delaying OM constriction, and ultimately disrupting the midcell positioning of MreB and FtsZ and interfering with the spatial regulation of PG synthesis and remodeling. IMPORTANCE By coordinating cell elongation and division, bacteria maintain their shape, support critical envelope functions, and orchestrate division. Regulatory and assembly systems have been implicated in these processes in some well-studied Gram-negative bacteria. However, we lack information on these processes and their conservation across the bacterial phylogeny. In R. sphaeroides and other α-proteobacteria, CenKR is an essential two-component system (TCS) that regulates the expression of genes known or predicted to function in cell envelope biosynthesis, elongation, and/or division. Here, we leverage unique features of CenKR to understand how increasing its activity impacts cell elongation/division and use antibiotics to identify how modulating the activity of this TCS leads to changes in cell morphology. Our results provide new insight into how CenKR activity controls the structure and function of the bacterial envelope, the localization of cell elongation and division machinery, and cellular processes in organisms with importance in health, host-microbe interactions, and biotechnology.
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Affiliation(s)
- Bryan D. Lakey
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - François Alberge
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Daniel Parrell
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Elizabeth R. Wright
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Cryo-Electron Microscopy Research Center,Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Daniel R. Noguera
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Timothy J. Donohue
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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9
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Thwaites O, Christianson BM, Cowan AJ, Jäckel F, Liu LN, Gardner AM. Unravelling the Roles of Integral Polypeptides in Excitation Energy Transfer of Photosynthetic RC-LH1 Supercomplexes. J Phys Chem B 2023; 127:7283-7290. [PMID: 37556839 PMCID: PMC10461223 DOI: 10.1021/acs.jpcb.3c04466] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/24/2023] [Indexed: 08/11/2023]
Abstract
Elucidating the photosynthetic processes that occur within the reaction center-light-harvesting 1 (RC-LH1) supercomplexes from purple bacteria is crucial for uncovering the assembly and functional mechanisms of natural photosynthetic systems and underpinning the development of artificial photosynthesis. Here, we examined excitation energy transfer of various RC-LH1 supercomplexes of Rhodobacter sphaeroides using transient absorption spectroscopy, coupled with lifetime density analysis, and studied the roles of the integral transmembrane polypeptides, PufX and PufY, in energy transfer within the RC-LH1 core complex. Our results show that the absence of PufX increases both the LH1 → RC excitation energy transfer lifetime and distribution due to the role of PufX in defining the interaction and orientation of the RC within the LH1 ring. While the absence of PufY leads to the conformational shift of several LH1 subunits toward the RC, it does not result in a marked change in the excitation energy transfer lifetime.
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Affiliation(s)
- Owen Thwaites
- Stephenson
Institute of Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, U.K.
- Department
of Physics, University of Liverpool, Liverpool L69 7ZE, U.K.
| | - Bern M. Christianson
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, U.K.
| | - Alexander J. Cowan
- Stephenson
Institute of Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, U.K.
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Frank Jäckel
- Stephenson
Institute of Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, U.K.
- Department
of Physics, University of Liverpool, Liverpool L69 7ZE, U.K.
| | - Lu-Ning Liu
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, U.K.
- College
of Marine Life Sciences, and Frontiers Science Center for Deep Ocean
Multispheres and Earth System, Ocean University
of China, Qingdao 266003, China
| | - Adrian M. Gardner
- Stephenson
Institute of Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, U.K.
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
- Early Career
Laser Laboratory, University of Liverpool, Liverpool L69 3BX, U.K.
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10
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Zhou Y, Gunn LH, Birch R, Andersson I, Whitney SM. Grafting Rhodobacter sphaeroides with red algae Rubisco to accelerate catalysis and plant growth. Nat Plants 2023; 9:978-986. [PMID: 37291398 DOI: 10.1038/s41477-023-01436-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 05/10/2023] [Indexed: 06/10/2023]
Abstract
Improving the carboxylation properties of Rubisco has primarily arisen from unforeseen amino acid substitutions remote from the catalytic site. The unpredictability has frustrated rational design efforts to enhance plant Rubisco towards the prized growth-enhancing carboxylation properties of red algae Griffithsia monilis GmRubisco. To address this, we determined the crystal structure of GmRubisco to 1.7 Å. Three structurally divergent domains were identified relative to the red-type bacterial Rhodobacter sphaeroides RsRubisco that, unlike GmRubisco, are expressed in Escherichia coli and plants. Kinetic comparison of 11 RsRubisco chimaeras revealed that incorporating C329A and A332V substitutions from GmRubisco Loop 6 (corresponding to plant residues 328 and 331) into RsRubisco increased the carboxylation rate (kcatc) by 60%, the carboxylation efficiency in air by 22% and the CO2/O2 specificity (Sc/o) by 7%. Plastome transformation of this RsRubisco Loop 6 mutant into tobacco enhanced photosynthesis and growth up to twofold over tobacco producing wild-type RsRubisco. Our findings demonstrate the utility of RsRubisco for the identification and in planta testing of amino acid grafts from algal Rubisco that can enhance the enzyme's carboxylase potential.
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Affiliation(s)
- Yu Zhou
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Laura H Gunn
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Rosemary Birch
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Inger Andersson
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
- Norwegian College of Fisheries Sciences, UiT Arctic University of Norway, Tromsø, Norway
- Institute of Biotechnology, Academy of Sciences of the Czech Republic, Biocev, Vestec, Czech Republic
| | - Spencer M Whitney
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.
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11
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Sugo Y, Ishikita H. Mechanism of Asparagine-Mediated Proton Transfer in Photosynthetic Reaction Centers. Biochemistry 2023; 62:1544-1552. [PMID: 37083399 PMCID: PMC10194076 DOI: 10.1021/acs.biochem.3c00013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/29/2023] [Indexed: 04/22/2023]
Abstract
In photosynthetic reaction centers from purple bacteria (PbRCs), light-induced charge separation leads to the reduction of the terminal electron acceptor quinone, QB. The reduction of QB to QB•- is followed by protonation via Asp-L213 and Ser-L223 in PbRC from Rhodobacter sphaeroides. However, Asp-L213 is replaced with nontitratable Asn-L222 and Asn-L213 in PbRCs from Thermochromatium tepidum and Blastochloris viridis, respectively. Here, we investigated the energetics of proton transfer along the asparagine-involved H-bond network using a quantum mechanical/molecular mechanical approach. The potential energy profile for the H-bond between H3O+ and the carbonyl O site of Asn-L222 shows that the proton is predominantly localized at the Asn-L222 moiety in the T. tepidum PbRC protein environment, easily forming the enol species. The release of the proton from the amide -NH2 site toward Ser-L232 via tautomerization suffers from the energy barrier. Upon reorientation of Asn-L222, the enol -OH site forms a short low-barrier H-bond with Ser-L232, facilitating protonation of QB•- in a Grotthuss-like mechanism. This is a basis of how asparagine or glutamine side chains function as acceptors/donors in proton transfer pathways.
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Affiliation(s)
- Yu Sugo
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroshi Ishikita
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
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12
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Wei RJ, Khaniya U, Mao J, Liu J, Batista VS, Gunner MR. Tools for analyzing protonation states and for tracing proton transfer pathways with examples from the Rb. sphaeroides photosynthetic reaction centers. Photosynth Res 2023; 156:101-112. [PMID: 36307598 DOI: 10.1007/s11120-022-00973-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Protons participate in many reactions. In proteins, protons need paths to move in and out of buried active sites. The vectorial movement of protons coupled to electron transfer reactions establishes the transmembrane electrochemical gradient used for many reactions, including ATP synthesis. Protons move through hydrogen bonded chains of waters and hydroxy side chains via the Grotthuss mechanism and by proton binding and release from acidic and basic residues. MCCE analysis shows that proteins exist in a large number of protonation states. Knowledge of the equilibrium ensemble can provide a rational basis for setting protonation states in simulations that fix them, such as molecular dynamics (MD). The proton path into the QB site in the bacterial reaction centers (RCs) of Rb. sphaeroides is analyzed by MD to provide an example of the benefits of using protonation states found by the MCCE program. A tangled web of side chains and waters link the cytoplasm to QB. MCCE analysis of snapshots from multiple trajectories shows that changing the input protonation state of a residue in MD biases the trajectory shifting the proton affinity of that residue. However, the proton affinity of some residues is more sensitive to the input structure. The proton transfer networks derived from different trajectories are quite robust. There are some changes in connectivity that are largely restricted to the specific residues whose protonation state is changed. Trajectories with QB•- are compared with earlier results obtained with QB [Wei et. al Photosynthesis Research volume 152, pages153-165 (2022)] showing only modest changes. While introducing new methods the study highlights the difficulty of establishing the connections between protein conformation.
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Affiliation(s)
- Rongmei Judy Wei
- Ph.D. Program in Chemistry, The Graduate Center, City University of New York, New York, NY, 10016, USA
- Department of Physics, City College of New York, New York, NY, 10031, USA
| | - Umesh Khaniya
- Department of Physics, City College of New York, New York, NY, 10031, USA
- Ph.D. Program in Physics, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Junjun Mao
- Department of Physics, City College of New York, New York, NY, 10031, USA
| | - Jinchan Liu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - M R Gunner
- Ph.D. Program in Chemistry, The Graduate Center, City University of New York, New York, NY, 10016, USA.
- Department of Physics, City College of New York, New York, NY, 10031, USA.
- Ph.D. Program in Physics, The Graduate Center of the City University of New York, New York, NY, 10016, USA.
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13
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Pitsawong W, Pádua RAP, Grant T, Hoemberger M, Otten R, Bradshaw N, Grigorieff N, Kern D. From primordial clocks to circadian oscillators. Nature 2023; 616:183-189. [PMID: 36949197 PMCID: PMC10076222 DOI: 10.1038/s41586-023-05836-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 02/13/2023] [Indexed: 03/24/2023]
Abstract
Circadian rhythms play an essential part in many biological processes, and only three prokaryotic proteins are required to constitute a true post-translational circadian oscillator1. The evolutionary history of the three Kai proteins indicates that KaiC is the oldest member and a central component of the clock2. Subsequent additions of KaiB and KaiA regulate the phosphorylation state of KaiC for time synchronization. The canonical KaiABC system in cyanobacteria is well understood3-6, but little is known about more ancient systems that only possess KaiBC. However, there are reports that they might exhibit a basic, hourglass-like timekeeping mechanism7-9. Here we investigate the primordial circadian clock in Rhodobacter sphaeroides, which contains only KaiBC, to elucidate its inner workings despite missing KaiA. Using a combination of X-ray crystallography and cryogenic electron microscopy, we find a new dodecameric fold for KaiC, in which two hexamers are held together by a coiled-coil bundle of 12 helices. This interaction is formed by the carboxy-terminal extension of KaiC and serves as an ancient regulatory moiety that is later superseded by KaiA. A coiled-coil register shift between daytime and night-time conformations is connected to phosphorylation sites through a long-range allosteric network that spans over 140 Å. Our kinetic data identify the difference in the ATP-to-ADP ratio between day and night as the environmental cue that drives the clock. They also unravel mechanistic details that shed light on the evolution of self-sustained oscillators.
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Affiliation(s)
- Warintra Pitsawong
- Howard Hughes Medical Institute and Department of Biochemistry, Brandeis University, Waltham, MA, USA
- Biomolecular Discovery, Relay Therapeutics, Cambridge, MA, USA
| | - Ricardo A P Pádua
- Howard Hughes Medical Institute and Department of Biochemistry, Brandeis University, Waltham, MA, USA
| | - Timothy Grant
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, Madison, WI, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Marc Hoemberger
- Howard Hughes Medical Institute and Department of Biochemistry, Brandeis University, Waltham, MA, USA
- Treeline Biosciences, Watertown, MA, USA
| | - Renee Otten
- Howard Hughes Medical Institute and Department of Biochemistry, Brandeis University, Waltham, MA, USA
- Treeline Biosciences, Watertown, MA, USA
| | - Niels Bradshaw
- Department of Biochemistry, Brandeis University, Waltham, MA, USA
| | - Nikolaus Grigorieff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Howard Hughes Medical Institute, RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Dorothee Kern
- Howard Hughes Medical Institute and Department of Biochemistry, Brandeis University, Waltham, MA, USA.
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14
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Mao HT, Chen LX, Zhang MY, Shi QY, Xu H, Zhang DY, Zhang ZW, Yuan M, Yuan S, Zhang HY, Su YQ, Chen YE. Melatonin improves the removal and the reduction of Cr(VI) and alleviates the chromium toxicity by antioxidative machinery in Rhodobacter sphaeroides. Environ Pollut 2023; 319:120973. [PMID: 36584859 DOI: 10.1016/j.envpol.2022.120973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/12/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
Bioremediation with photosynthetic bacteria (PSB) is thought to be a promising removal method for hexavalent chromium [Cr(VI)]-containing wastewater. In the present study, Rhodobacter sphaeroides (R. sphaeroides) SC01 was used for the investigation of Cr(VI) removal in Cr(VI)-contaminated solution in the presence of melatonin. It was found that exogenous melatonin alleviated oxidative damage to R. sphaeroides SC01, increased Cr (VI) absorption capacity of cell membrane, and improved the reduction efficiency of Cr(VI) via the activation of chromate reductants. The results showed that melatonin could further promote the increase in Cr(VI) removal efficiency, reaching up to 97.8%. Furthermore, melatonin application resulted in 296.9%, 44.4%, and 69.7% upregulation of ascorbic acid (AsA), glutathione (GSH), and cysteine (Cys) relative to non-melatioin treated R. sphaeroides SC01 at 48 h. In addition, the resting cells, cell-free supernatants (CFS), and cell-free extracts (CFE) with melatonin had a higher Cr(VI) removal rate of 18.6%, 82.0%, and 15.2% compared with non-melatonin treated R. sphaeroides SC01. Fourier transform infrared spectroscopy (FTIR) revealed that melatonin increased the binding of Cr(III) with PO43- and CO groups on cell membrane of R. sphaeroides SC01. X-ray diffractometer (XRD) analysis demonstrated that melatonin remarkably bioprecipitated the production of CrPO4·6H2O in R. sphaeroides SC01. Hence, these results indicated that melatonin plays the important role in the reduction and uptake of Cr(VI), demonstrating it is a great promising strategy for the management of Cr(VI) contaminated wastewater in photosynthetic bacteria.
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Affiliation(s)
- Hao-Tian Mao
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China
| | - Lun-Xing Chen
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China
| | - Meng-Ying Zhang
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China
| | - Qiu-Yun Shi
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China
| | - Hong Xu
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China
| | - Da-Yan Zhang
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China
| | - Zhong-Wei Zhang
- College of Resources, Sichuan Agricultural University, 611130, Chengdu, China
| | - Ming Yuan
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China
| | - Shu Yuan
- College of Resources, Sichuan Agricultural University, 611130, Chengdu, China
| | - Huai-Yu Zhang
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China
| | - Yan-Qiu Su
- College of Life Science, Sichuan Normal University, 610066, Chengdu, China
| | - Yang-Er Chen
- College of Life Science, Sichuan Agricultural University, 625014, Ya'an, China.
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15
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Allen JP, Chamberlain KD, Williams JC. Identification of amino acid residues in a proton release pathway near the bacteriochlorophyll dimer in reaction centers from Rhodobacter sphaeroides. Photosynth Res 2023; 155:23-34. [PMID: 36197600 DOI: 10.1007/s11120-022-00968-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
Insight into control of proton transfer, a crucial attribute of cellular functions, can be gained from investigations of bacterial reaction centers. While the uptake of protons associated with the reduction of the quinone is well characterized, the release of protons associated with the oxidized bacteriochlorophyll dimer has been poorly understood. Optical spectroscopy and proton release/uptake measurements were used to examine the proton release characteristics of twelve mutant reaction centers, each containing a change in an amino acid residue near the bacteriochlorophyll dimer. The mutant reaction centers had optical spectra similar to wild-type and were capable of transferring electrons to the quinones after light excitation of the bacteriochlorophyll dimer. They exhibited a large range in the extent of proton release and in the slow recovery of the optical signal for the oxidized dimer upon continuous illumination. Key roles were indicated for six amino acid residues, Thr L130, Asp L155, Ser L244, Arg M164, Ser M190, and His M193. Analysis of the results points to a hydrogen-bond network that contains these residues, with several additional residues and bound water molecules, forming a proton transfer pathway. In addition to proton transfer, the properties of the pathway are proposed to be responsible for the very slow charge recombination kinetics observed after continuous illumination. The characteristics of this pathway are compared to proton transfer pathways near the secondary quinone as well as those found in photosystem II and cytochrome c oxidase.
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Affiliation(s)
- J P Allen
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA.
| | - K D Chamberlain
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
| | - J C Williams
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
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16
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Spanka DT, Grützner J, Jäger A, Klug G. A Small RNA, UdsC, Interacts with the R poHII mRNA and Affects the Motility and Stress Resistance of Rhodobacter sphaeroides. Int J Mol Sci 2022; 23:ijms232415486. [PMID: 36555125 PMCID: PMC9779115 DOI: 10.3390/ijms232415486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
sRNAs have an important role in the regulation of bacterial gene expression. The sRNA, UdsC, of Rhodobacter sphaeroides is derived from the 3' UTR of the RSP_7527 mRNA, which encodes a hypothetical protein. Here, we showed the effect of UdsC on the resistance of Rhodobacter sphaeroides to hydrogen peroxide and on its motility. In vitro binding assays supported the direct interaction of UdsC with the 5' UTR of the rpoHII mRNA. RpoHII is an alternative sigma factor with an important role in stress responses in R. sphaeroides, including its response to hydrogen peroxide. We also demonstrated that RpoHII controls the expression of the torF gene, which encodes an important regulator of motility genes. This strongly suggested that the observed effect of UdsC on TorF expression is indirect and mediated by RpoHII.
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17
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Lee S, Rim Lee Y, Lee WH, Youn Lee S, Moon M, Woo Park G, Min K, Lee J, Lee JS. Valorization of CO 2 to β-farnesene in Rhodobacter sphaeroides. Bioresour Technol 2022; 363:127955. [PMID: 36115510 DOI: 10.1016/j.biortech.2022.127955] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/06/2022] [Accepted: 09/08/2022] [Indexed: 06/15/2023]
Abstract
The valorization of CO2 into valuable products is a sustainable strategy to help overcome the climate crisis. In particular, biological conversion is attractive as it can produce long-chain hydrocarbons such as terpenoids. This study reports the high yield of β-farnesene production from CO2 by expressing heterologous β-farnesene synthase (FS) into Rhodobacter sphaeroides. To increase the expression of FS, a strong active promoter and a ribosome binding site (RBS) were engineered. Moreover, β-farnesene production was improved further through the supply of exogenous antioxidants and additional nutrients. Finally, β-farnesene was produced from CO2 at a titer of 44.53 mg/L and yield of 234.08 mg/g, values that were correspondingly 23 times and 46 times higher than those from the initial production of β-farnesene. Altogether, the results here suggest that the autotrophic production of β-farnesene can provide a starting point for achieving a circular carbon economy.
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Affiliation(s)
- Sangmin Lee
- Gwangju Bio/Energy Research and Development Center, Korea Institute of Energy Research, Gwangju 61003, Republic of Korea
| | - Yu Rim Lee
- Gwangju Bio/Energy Research and Development Center, Korea Institute of Energy Research, Gwangju 61003, Republic of Korea; Interdisciplinary Program of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Won-Heong Lee
- Interdisciplinary Program of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Soo Youn Lee
- Gwangju Bio/Energy Research and Development Center, Korea Institute of Energy Research, Gwangju 61003, Republic of Korea
| | - Myounghoon Moon
- Gwangju Bio/Energy Research and Development Center, Korea Institute of Energy Research, Gwangju 61003, Republic of Korea
| | - Gwon Woo Park
- Gwangju Bio/Energy Research and Development Center, Korea Institute of Energy Research, Gwangju 61003, Republic of Korea
| | - Kyoungseon Min
- Gwangju Bio/Energy Research and Development Center, Korea Institute of Energy Research, Gwangju 61003, Republic of Korea
| | - Juah Lee
- Gwangju Bio/Energy Research and Development Center, Korea Institute of Energy Research, Gwangju 61003, Republic of Korea
| | - Jin-Suk Lee
- Gwangju Bio/Energy Research and Development Center, Korea Institute of Energy Research, Gwangju 61003, Republic of Korea.
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18
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Zabelin AA, Kovalev VB, Shkuropatov AY. On the Mechanism of Selective Chemical Exchange of Bacteriopheophytins in the Reaction Centers of Rhodobacter sphaeroides R-26. Biochemistry (Mosc) 2022; 87:1119-1129. [PMID: 36273880 DOI: 10.1134/s0006297922100054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/11/2022] [Accepted: 08/10/2022] [Indexed: 06/16/2023]
Abstract
To elucidate the mechanism of site-selective chemical replacement of chromophores in the reaction centers (RCs) of photosynthetic bacteria by external pigments, we investigated how the efficiency of incorporation of plant pheophytin a (Pheo) into the binding sites for bacteriopheophytin a molecules (BPheo) in the isolated Rhodobacter sphaeroides R-26 RCs depended on the incubation medium temperature, Pheo aggregation state, and the presence of organic solvent (acetone). When Pheo was in a form of monomers in free detergent micelles in a water-detergent incubation medium, the degree of selective replacement of photochemically inactive BPheo HB molecules upon incubation of the RC/Pheo mixture at 5°C was ~15%. The exchange efficiency increased to 40% upon incubation at 25°C and reached 100% at the same temperature when 10% acetone was added to the incubation medium. At both 5 and 25°C, the degree of pigment exchange increased approximately twice, when a mixture of Pheo monomers and dimers in the presence of 10% acetone was used as the incubation medium. The removal of acetone from this medium with the preservation of pigment forms led to a significant decrease in the efficiency of Pheo incorporation. The effect of acetone on the pigment exchange was also observed at an elevated incubation temperature (43.5°C), when functionally active BPheo HA molecules were partially replaced. The results are discussed in terms of the mechanism according to which (i) the temperature-dependent internal movements of the RC protein facilitate the release of the BPheo molecule from the binding site with simultaneous insertion of the Pheo molecule into the same site in a coupled process, (ii) the role of temperature largely depends on the steric accessibility of binding pockets in the RC protein, (iii) the incorporation of Pheo occurs from a pool of monomeric molecules included in the RC-detergent micelles, and (iv) the presence of acetone in the incubation medium facilitates the exchange of Pheo monomers between micelles in the solution and the detergent belt of the RC complex.
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Affiliation(s)
- Alexey A Zabelin
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
| | - Vyacheslav B Kovalev
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Anatoly Ya Shkuropatov
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
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19
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Fufina TY, Tretchikova OA, Khristin AM, Khatypov RA, Vasilieva LG. Properties of Mutant Photosynthetic Reaction Centers of Purple Non-Sulfur Bacteria Cereibacter sphaeroides with M206 Ile→Gln Substitution. Biochemistry (Mosc) 2022; 87:1149-1158. [PMID: 36273883 DOI: 10.1134/s000629792210008x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 08/14/2022] [Accepted: 08/14/2022] [Indexed: 06/16/2023]
Abstract
In the structure of photosynthetic reaction center (RC) of the purple bacterium Cereibacter sphaeroides the highly conserved amino acid residue Ile-M206 is located near the bacteriochlorophyll dimer P, which is the primary electron donor, and the monomeric bacteriochlorophyll BA, which is the nearest electron acceptor. Since Ile-M206 is close to the C2-acetyl group of bacteriochlorophyll PB, the hydroxyl group of Tyr-M210, and to the C9-keto group of bacteriochlorophyll BA, as well as to the water molecule near the latter group, this site can be used for introducing mutations in order to study mechanisms of primary photochemical processes in the RC. Previously it was shown that the Ile→Glu substitution at the M204 position (analog of M206 in the RC of C. sphaeroides) in the RC of the closely related purple non-sulfur bacterium Rhodobacter capsulatus significantly affected kinetics of the P+HA- state formation, whereas the M204 Ile→Gln substitution led to the loss of BChl BA molecule from the complex structure. In the present work, it is shown that the single I(M206)Q or double I(M206)Q + F(M208)A amino acid substitutions in the RC of C. sphaeroides do not change the pigment composition and do not markedly influence redox potential of the primary electron donor. However, substitution of Ile M206 by Gln affected positions and amplitudes of the absorption bands of bacteriochlorophylls, increased lifetime of the primary electron donor P* excited state from 3.1 ps to 22 ps, and decreased quantum yield of the P+QA- state formation to 60%. These data suggest significant changes in the pigment-protein interactions in the vicinity of the primary electron donor P and the nearest electron acceptor BA. A considerable decrease was also noticed in the resistance of the mutant RC to thermal denaturation, which was more pronounced in the RC with the double substitution I(M206)Q + F(M208)A. This was likely associated with the disruption of the dense packing of the protein near bacteriochlorophylls PB and BA. Possible reasons for different effects of identical mutations on the properties of two highly homologous RCs from closely related purple non-sulfur bacteria are discussed.
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Affiliation(s)
- Tatiana Yu Fufina
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Olga A Tretchikova
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Anton M Khristin
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Ravil A Khatypov
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Lyudmila G Vasilieva
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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20
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Lakey BD, Myers KS, Alberge F, Mettert EL, Kiley PJ, Noguera DR, Donohue TJ. The essential Rhodobacter sphaeroides CenKR two-component system regulates cell division and envelope biosynthesis. PLoS Genet 2022; 18:e1010270. [PMID: 35767559 PMCID: PMC9275681 DOI: 10.1371/journal.pgen.1010270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 07/12/2022] [Accepted: 05/20/2022] [Indexed: 12/13/2022] Open
Abstract
Bacterial two-component systems (TCSs) often function through the detection of an extracytoplasmic stimulus and the transduction of a signal by a transmembrane sensory histidine kinase. This kinase then initiates a series of reversible phosphorylation modifications to regulate the activity of a cognate, cytoplasmic response regulator as a transcription factor. Several TCSs have been implicated in the regulation of cell cycle dynamics, cell envelope integrity, or cell wall development in Escherichia coli and other well-studied Gram-negative model organisms. However, many α-proteobacteria lack homologs to these regulators, so an understanding of how α-proteobacteria orchestrate extracytoplasmic events is lacking. In this work we identify an essential TCS, CenKR (Cell envelope Kinase and Regulator), in the α-proteobacterium Rhodobacter sphaeroides and show that modulation of its activity results in major morphological changes. Using genetic and biochemical approaches, we dissect the requirements for the phosphotransfer event between CenK and CenR, use this information to manipulate the activity of this TCS in vivo, and identify genes that are directly and indirectly controlled by CenKR in Rb. sphaeroides. Combining ChIP-seq and RNA-seq, we show that the CenKR TCS plays a direct role in maintenance of the cell envelope, regulates the expression of subunits of the Tol-Pal outer membrane division complex, and indirectly modulates the expression of peptidoglycan biosynthetic genes. CenKR represents the first TCS reported to directly control the expression of Tol-Pal machinery genes in Gram-negative bacteria, and we predict that homologs of this TCS serve a similar function in other closely related organisms. We propose that Rb. sphaeroides genes of unknown function that are directly regulated by CenKR play unknown roles in cell envelope biosynthesis, assembly, and/or remodeling in this and other α-proteobacteria. The bacterial cell envelope is home to an array of important functions including energy conservation, motility, influx/efflux of nutrients and toxins, modulation of cell morphology and division, cell-cell interaction, and biofilm formation. Consequently, it is a major target of antibiotics and antimicrobial agents that inhibit these essential processes. Key to the recognition of environmental stressors or stimuli are bacterial TCSs, however systems that monitor or directly regulate cell envelope assembly and homeostasis are not widely conserved amongst bacteria. Here, we use Rhodobacter sphaeroides as a model to investigate the function of the CenKR TCS in this and other α-proteobacteria. We show that this essential TCS plays a key role in maintenance of the cell envelope through the regulation of outer membrane integrity and division, cell wall remodeling and homeostasis, and an alternate sigma factor that controls global cellular stress response. We provide evidence that this TCS and its function is widely conserved in α-proteobacteria and identify genes of unknown function as candidates for the study of cell envelope assembly in this and related bacteria.
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Affiliation(s)
- Bryan D. Lakey
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kevin S. Myers
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - François Alberge
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Erin L. Mettert
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Patricia J. Kiley
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Daniel R. Noguera
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Timothy J. Donohue
- Wisconsin Energy Institute, Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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21
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Aal-Aaboda MS, Abu Raghif AR, Hadi NR. Renoprotective Potential of the Ultra-Pure Lipopolysaccharide from Rhodobacter Sphaeroides on Acutely Injured Kidneys in an Animal Model. Arch Razi Inst 2021; 76:1755-1764. [PMID: 35546979 PMCID: PMC9083871 DOI: 10.22092/ari.2021.356202.1803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 10/15/2021] [Indexed: 06/15/2023]
Abstract
One of the main causes of acute kidney injury is ischemic reperfusion injury (IRI). Inflammatory response, apoptotic damages, and oxidative stress-related injuries are all involved in the pathogenesis of IRI. Toll-like receptors (TLR) are strongly associated with IRIs, especially TLR4, which is markedly induced in response to IRI. Accordingly, the current study aimed to investigate the potential renoprotective effect of ultrapure lipopolysaccharide from Rhodobacter sphaeroides (ULPS-RS) at two doses in an animal model of bilateral IRI. A total of 30 adult male rats were divided randomly into five equal groups of control (laparotomy plus bilateral renal IRI), vehicle (same as the control group, but pretreated with the vehicle), sham (laparotomy only), ULPS-RS (same as the control group, but pretreated with 0.1 mg/kg of ULPS-RS), and ULPS-RSH (same as the control group, but pretreated with 0.2 mg/kg of ULPS-RS). Subsequent to 30 min of ischemia and 2 h of reperfusion, serum samples were collected for measuring urea, creatinine, and neutrophil gelatinase-associated lipocalin. Afterward, tissue samples were obtained from all animals to measure inflammatory mediators (interleukin 6, interleukin 1β, and tumor necrosis factor α), oxidative stress marker (8-isoprostane), apoptosis mediators (B cell lymphoma 2 [Bcl2]), and Bcl2-associated X protein (Bax). In the control group, all of the measured parameters were significantly elevated in response to IRI, except for Bcl2, which decreased significantly. On the other hand, exactly opposite effects were observed in the ULPS-RS treated groups indicating the nephroprotective effect of this compound against IRI at both tested doses. The findings reveal for the first time that ULPS-RS has the therapeutic potential of attenuating the renal dysfunction induced by IRI.
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Affiliation(s)
- M S Aal-Aaboda
- Department of Pharmacology, Faculty of Pharmacy, University of Misan, Iraq
| | - A R Abu Raghif
- Department of Pharmacology, Faculty of Medicine, Al-Nahrain University, Iraq
| | - N R Hadi
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Kufa, Iraq
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22
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Eisenhardt KMH, Remes B, Grützner J, Spanka DT, Jäger A, Klug G. A Complex Network of Sigma Factors and sRNA StsR Regulates Stress Responses in R. sphaeroides. Int J Mol Sci 2021; 22:ijms22147557. [PMID: 34299177 PMCID: PMC8307010 DOI: 10.3390/ijms22147557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/01/2021] [Accepted: 07/09/2021] [Indexed: 11/16/2022] Open
Abstract
Adaptation of bacteria to a changing environment is often accompanied by remodeling of the transcriptome. In the facultative phototroph Rhodobacter sphaeroides the alternative sigma factors RpoE, RpoHI and RpoHII play an important role in a variety of stress responses, including heat, oxidative stress and nutrient limitation. Photooxidative stress caused by the simultaneous presence of chlorophylls, light and oxygen is a special challenge for phototrophic organisms. Like alternative sigma factors, several non-coding sRNAs have important roles in the defense against photooxidative stress. RNAseq-based transcriptome data pointed to an influence of the stationary phase-induced StsR sRNA on levels of mRNAs and sRNAs with a role in the photooxidative stress response. Furthermore, StsR also affects expression of photosynthesis genes and of genes for regulators of photosynthesis genes. In vivo and in vitro interaction studies revealed that StsR, that is under control of the RpoHI and RpoHII sigma factors, targets rpoE mRNA and affects its abundance by altering its stability. RpoE regulates expression of the rpoHII gene and, consequently, expression of stsR. These data provide new insights into a complex regulatory network of protein regulators and sRNAs involved in defense against photooxidative stress and the regulation of photosynthesis genes.
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23
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Grützner J, Remes B, Eisenhardt KMH, Scheller D, Kretz J, Madhugiri R, McIntosh M, Klug G. sRNA-mediated RNA processing regulates bacterial cell division. Nucleic Acids Res 2021; 49:7035-7052. [PMID: 34125915 PMCID: PMC8266604 DOI: 10.1093/nar/gkab491] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/17/2021] [Accepted: 05/28/2021] [Indexed: 01/16/2023] Open
Abstract
Tight control of cell division is essential for survival of most organisms. For prokaryotes, the regulatory mechanisms involved in the control of cell division are mostly unknown. We show that the small non-coding sRNA StsR has an important role in controlling cell division and growth in the alpha-proteobacterium Rhodobacter sphaeroides. StsR is strongly induced by stress conditions and in stationary phase by the alternative sigma factors RpoHI/HII, thereby providing a regulatory link between cell division and environmental cues. Compared to the wild type, a mutant lacking StsR enters stationary phase later and more rapidly resumes growth after stationary phase. A target of StsR is UpsM, the most abundant sRNA in the exponential phase. It is derived from partial transcriptional termination within the 5' untranslated region of the mRNA of the division and cell wall (dcw) gene cluster. StsR binds to UpsM as well as to the 5' UTR of the dcw mRNA and the sRNA-sRNA and sRNA-mRNA interactions lead to a conformational change that triggers cleavage by the ribonuclease RNase E, affecting the level of dcw mRNAs and limiting growth. These findings provide interesting new insights into the role of sRNA-mediated regulation of cell division during the adaptation to environmental changes.
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Affiliation(s)
- Julian Grützner
- Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Bernhard Remes
- Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Katrin M H Eisenhardt
- Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Daniel Scheller
- Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Jonas Kretz
- Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Ramakanth Madhugiri
- Institute of Medical Virology, University of Giessen, Schubertstr. 81, D-35392 Giessen, Germany
| | - Matthew McIntosh
- Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, University of Giessen, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
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24
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Qu Y, Su A, Li Y, Meng Y, Chen Z. Manipulation of the Regulatory Genes ppsR and prrA in Rhodobacter sphaeroides Enhances Lycopene Production. J Agric Food Chem 2021; 69:4134-4143. [PMID: 33813825 DOI: 10.1021/acs.jafc.0c08158] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Rhodobacter sphaeroides is a non-sulfur purple bacterium with great metabolic versatility, capable of producing a variety of valuable compounds that include carotenoids and CoQ10. In order to enhance lycopene production, we deleted the photosynthetic gene cluster repressor ppsR from a lycopene-producing Rb. sphaeroides strain (RL1) constructed in a previous study to break the control of carotenoid synthesis by the oxygen level. Also, lycopene production was further increased by overexpression of the activator prrA. The superior lycopene producer DppsR/OprrA thus obtained had a high growth rate and a lycopene production of 150.15 mg/L with a yield of 21.45 mg/g dry cell weight (DCW) under high oxygen conditions; these values were ≥6.85-fold higher than those of RL1 (19.13 mg/L; 3.32 mg/g DCW). Our findings indicate that elimination of oxygen repression led to more efficient lycopene production by DppsR/OprrA and that its increased productivity under high oxygen conditions makes it a potentially useful strain for industrial-scale lycopene production.
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Affiliation(s)
- Yuling Qu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Anping Su
- Shaanxi Engineering Laboratory for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Ying Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yonghong Meng
- Shaanxi Engineering Laboratory for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Zhi Chen
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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25
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Grützner J, Billenkamp F, Spanka DT, Rick T, Monzon V, Förstner KU, Klug G. The small DUF1127 protein CcaF1 from Rhodobacter sphaeroides is an RNA-binding protein involved in sRNA maturation and RNA turnover. Nucleic Acids Res 2021; 49:3003-3019. [PMID: 33706375 PMCID: PMC8034643 DOI: 10.1093/nar/gkab146] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 02/10/2021] [Accepted: 02/26/2021] [Indexed: 12/16/2022] Open
Abstract
Many different protein domains are conserved among numerous species, but their function remains obscure. Proteins with DUF1127 domains number >17 000 in current databases, but a biological function has not yet been assigned to any of them. They are mostly found in alpha- and gammaproteobacteria, some of them plant and animal pathogens, symbionts or species used in industrial applications. Bioinformatic analyses revealed similarity of the DUF1127 domain of bacterial proteins to the RNA binding domain of eukaryotic Smaug proteins that are involved in RNA turnover and have a role in development from Drosophila to mammals. This study demonstrates that the 71 amino acid DUF1127 protein CcaF1 from the alphaproteobacterium Rhodobacter sphaeroides participates in maturation of the CcsR sRNAs that are processed from the 3' UTR of the ccaF mRNA and have a role in the oxidative stress defense. CcaF1 binds to many cellular RNAs of different type, several mRNAs with a function in cysteine / methionine / sulfur metabolism. It affects the stability of the CcsR RNAs and other non-coding RNAs and mRNAs. Thus, the widely distributed DUF1127 domain can mediate RNA-binding, affect stability of its binding partners and consequently modulate the bacterial transcriptome, thereby influencing different physiological processes.
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Affiliation(s)
- Julian Grützner
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
| | - Fabian Billenkamp
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
- Institute of Animal Nutrition, Friedrich Loeffler Institute, Bundesalle 37, D-38116 Braunschweig, Germany
| | - Daniel-Timon Spanka
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
| | - Tim Rick
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
| | | | - Konrad U Förstner
- ZB MED-Information Center of Life Science, Germany
- Institute of Information Science, TH Köln, University of Applied Science, Gustav-Heinemann-Ufer 54, D-50968 Köln, Cologne, Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Heinrich-Buff-Ring 26–32, D-35292 Giessen, Germany
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26
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Lisitskaya L, Petushkov I, Esyunina D, Aravin A, Kulbachinskiy A. Recognition of double-stranded DNA by the Rhodobacter sphaeroides Argonaute protein. Biochem Biophys Res Commun 2020; 533:1484-1489. [PMID: 33333714 DOI: 10.1016/j.bbrc.2020.10.051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 10/18/2020] [Indexed: 10/23/2022]
Abstract
In contrast to eukaryotic Argonaute proteins that act on RNA targets, prokaryotic Argonautes (pAgos) can target DNA, using either small RNA or small DNA guides for its recognition. Since pAgos can recognize only a single strand of DNA and lack a helicase activity, it remains unknown how double-stranded DNA can be bound both in vitro and in vivo. Here, using in vitro reconstitution and footprinting assays we analyze formation of specific complexes with target DNA by a catalytically inactive pAgo, RsAgo from Rhodobacter sphaeroides programmed with small guide RNAs. We showed that RsAgo can recognize a specific site in double-stranded DNA after stepwise reconstitution of the complex from individual oligonucleotides or after prior melting of the DNA target. When bound, RsAgo stabilizes an open DNA bubble corresponding to the length of the guide molecule and protects the target DNA from nuclease cleavage. The results suggest that RsAgo and, possibly, other RNA-guided pAgos cannot directly attack double-stranded DNA and likely require DNA opening by other cellular processes for their action.
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Affiliation(s)
- Lidia Lisitskaya
- Institute of Molecular Genetics, NRC "Kurchatov Institute", Moscow, 123182, Russia
| | - Ivan Petushkov
- Institute of Molecular Genetics, NRC "Kurchatov Institute", Moscow, 123182, Russia
| | - Daria Esyunina
- Institute of Molecular Genetics, NRC "Kurchatov Institute", Moscow, 123182, Russia
| | - Alexei Aravin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
| | - Andrey Kulbachinskiy
- Institute of Molecular Genetics, NRC "Kurchatov Institute", Moscow, 123182, Russia.
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27
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Białek R, Thakur K, Ruff A, Jones MR, Schuhmann W, Ramanan C, Gibasiewicz K. Insight into Electron Transfer from a Redox Polymer to a Photoactive Protein. J Phys Chem B 2020; 124:11123-11132. [PMID: 33236901 PMCID: PMC7735723 DOI: 10.1021/acs.jpcb.0c08714] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/10/2020] [Indexed: 11/29/2022]
Abstract
Biohybrid photoelectrochemical systems in photovoltaic or biosensor applications have gained considerable attention in recent years. While the photoactive proteins engaged in such systems usually maintain an internal charge separation quantum yield of nearly 100%, the subsequent steps of electron and hole transfer beyond the protein often limit the overall system efficiency and their kinetics remain largely uncharacterized. To reveal the dynamics of one of such charge-transfer reactions, we report on the reduction of Rhodobacter sphaeroides reaction centers (RCs) by Os-complex-modified redox polymers (P-Os) characterized using transient absorption spectroscopy. RCs and P-Os were mixed in buffered solution in different molar ratios in the presence of a water-soluble quinone as an electron acceptor. Electron transfer from P-Os to the photoexcited RCs could be described by a three-exponential function, the fastest lifetime of which was on the order of a few microseconds, which is a few orders of magnitude faster than the internal charge recombination of RCs with fully separated charge. This was similar to the lifetime for the reduction of RCs by their natural electron donor, cytochrome c2. The rate of electron donation increased with increasing ratio of polymer to protein concentrations. It is proposed that P-Os and RCs engage in electrostatic interactions to form complexes, the sizes of which depend on the polymer-to-protein ratio. Our findings throw light on the processes within hydrogel-based biophotovoltaic devices and will inform the future design of materials optimally suited for this application.
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Affiliation(s)
- Rafał Białek
- Faculty
of Physics, Adam Mickiewicz University, Poznań, ul. Uniwersytetu
Poznańskiego 2, 61-614 Poznań, Poland
| | - Kalyani Thakur
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Adrian Ruff
- Analytical
Chemistry—Center for Electrochemical Sciences, Faculty of Biochemistry
and Chemistry, Faculty of Biochemistry and Chemistry, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Michael R. Jones
- School
of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, U.K.
| | - Wolfgang Schuhmann
- Analytical
Chemistry—Center for Electrochemical Sciences, Faculty of Biochemistry
and Chemistry, Faculty of Biochemistry and Chemistry, Ruhr-University Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Charusheela Ramanan
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Krzysztof Gibasiewicz
- Faculty
of Physics, Adam Mickiewicz University, Poznań, ul. Uniwersytetu
Poznańskiego 2, 61-614 Poznań, Poland
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28
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Khristin AM, Zabelin AA, Fufina TY, Khatypov RA, Proskuryakov II, Shuvalov VA, Shkuropatov AY, Vasilieva LG. Mutation H(M202)L does not lead to the formation of a heterodimer of the primary electron donor in reaction centers of Rhodobacter sphaeroides when combined with mutation I(M206)H. Photosynth Res 2020; 146:109-121. [PMID: 32125564 DOI: 10.1007/s11120-020-00728-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/17/2020] [Indexed: 06/10/2023]
Abstract
In photosynthetic reaction centers (RCs) of purple bacteria, conserved histidine residues [His L173 and His M202 in Rhodobacter (Rba.) sphaeroides] are known to serve as fifth axial ligands to the central Mg atom of the bacteriochlorophyll (BChl) molecules (PA and PB, respectively) that constitute the homodimer (BChl/BChl) primary electron donor P. In a number of previous studies, it has been found that replacing these residues with leucine, which cannot serve as a ligand to the Mg ion of BChl, leads to the assembly of heterodimer RCs with P represented by the BChl/BPheo pair. Here, we show that a homodimer P is assembled in Rba. sphaeroides RCs if the mutation H(M202)L is combined with the mutation of isoleucine to histidine at position M206 located in the immediate vicinity of PB. The resulting mutant H(M202)L/I(M206)H RCs are characterized using pigment analysis, redox titration, and a number of spectroscopic methods. It is shown that, compared to wild-type RCs, the double mutation causes significant changes in the absorption spectrum of the P homodimer and the electronic structure of the radical cation P+, but has only minor effect on the pigment composition, the P/P+ midpoint potential, and the initial electron-transfer reaction. The results are discussed in terms of the nature of the axial ligand to the Mg of PB in mutant H(M202)L/I(M206)H RCs and the possibility of His M202 participation in the previously proposed through-bond route for electron transfer from the excited state P* to the monomeric BChl BA in wild-type RCs.
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Affiliation(s)
- Anton M Khristin
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russian Federation
| | - Alexey A Zabelin
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russian Federation
| | - Tatiana Yu Fufina
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russian Federation
| | - Ravil A Khatypov
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russian Federation
| | - Ivan I Proskuryakov
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russian Federation
| | - Vladimir A Shuvalov
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russian Federation
| | - Anatoly Ya Shkuropatov
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russian Federation
| | - Lyudmila G Vasilieva
- Institute of Basic Biological Problems of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, 142290, Moscow, Russian Federation.
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29
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Maróti P, Kovács IA, Kis M, Smart JL, Iglói F. Correlated clusters of closed reaction centers during induction of intact cells of photosynthetic bacteria. Sci Rep 2020; 10:14012. [PMID: 32814810 PMCID: PMC7438532 DOI: 10.1038/s41598-020-70966-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 07/29/2020] [Indexed: 01/18/2023] Open
Abstract
Antenna systems serve to absorb light and to transmit excitation energy to the reaction center (RC) in photosynthetic organisms. As the emitted (bacterio)chlorophyll fluorescence competes with the photochemical utilization of the excitation, the measured fluorescence yield is informed by the migration of the excitation in the antenna. In this work, the fluorescence yield concomitant with the oxidized dimer (P+) of the RC were measured during light excitation (induction) and relaxation (in the dark) for whole cells of photosynthetic bacterium Rhodobacter sphaeroides lacking cytochrome c2 as natural electron donor to P+ (mutant cycA). The relationship between the fluorescence yield and P+ (fraction of closed RC) showed deviations from the standard Joliot-Lavergne-Trissl model: (1) the hyperbola is not symmetric and (2) exhibits hysteresis. These phenomena originate from the difference between the delays of fluorescence relative to P+ kinetics during induction and relaxation, and in structural terms from the non-random distribution of the closed RCs during induction. The experimental findings are supported by Monte Carlo simulations and by results from statistical physics based on random walk approximations of the excitation in the antenna. The applied mathematical treatment demonstrates the generalization of the standard theory and sets the stage for a more adequate description of the long-debated kinetics of fluorescence and of the delicate control and balance between efficient light harvest and photoprotection in photosynthetic organisms.
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Affiliation(s)
- Péter Maróti
- Department of Medical Physics and Informatics, Szeged University, Rerrich Béla tér 1., 6720, Szeged, Hungary.
| | - István A Kovács
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, 60208-3112, USA
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, P.O. Box 49, 1525, Budapest, Hungary
- Department of Network and Data Science, Central European University, Budapest, 1051, Hungary
| | - Mariann Kis
- Department of Medical Physics and Informatics, Szeged University, Rerrich Béla tér 1., 6720, Szeged, Hungary
| | - James L Smart
- Department of Biological Sciences, University of Tennessee at Martin, Martin, TN, 38238, USA
| | - Ferenc Iglói
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, P.O. Box 49, 1525, Budapest, Hungary
- Institute of Theoretical Physics, Szeged University, 6720, Szeged, Hungary
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30
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Modafferi D, Zazubovich V, Kálmán L. Bound detergent molecules in bacterial reaction centers facilitate detection of tetryl explosive. Photosynth Res 2020; 145:145-157. [PMID: 32632533 DOI: 10.1007/s11120-020-00770-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Bacterial reaction centers (BRC) from Rhodobacter sphaeroides were found to accelerate, about 100-fold, the reaction between tetryl (2,4,6-trinitrophenylmethylnitramine) explosive and n-lauryl-N-N-dimethylamine-N-oxide (LDAO) that results in the formation of picric acid-like product with characteristic UV-VIS absorption spectrum with peaks at 345 and 415 nm. Moreover, this product also affects the spectra of BRC cofactors in the NIR spectral region and stabilizes the conformational changes associated with slow charge recombination. The evolution of the NIR absorption changes correlated with the kinetics of the product formation. Comparison between the wild-type and the R26 carotenoid-less strain indicates that tetryl-LDAO reaction is roughly five times faster for R26, which allows for identifying the carotenoid binding site as the optimal reaction site. Another, less-defined reaction site is located in the BRC's hydrophobic cavity. These effects are highly selective for tetryl and not observed for several other widespread nitric explosives; slowed-down charge recombination allows for distinguishing between tetryl and QB-site herbicides. The current limit of detection is in the ppb range or ~ 100 nM. Details of the molecular mechanisms of the reactions and perspectives of using these effects in bioassays or biosensors for explosives detection are also discussed.
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Affiliation(s)
- Daniel Modafferi
- Department of Physics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada
- Department of Chemical Engineering, McGill University, Montreal, QC, Canada
| | - Valter Zazubovich
- Department of Physics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada.
| | - László Kálmán
- Department of Physics, Concordia University, 7141 Sherbrooke Street West, Montreal, QC, H4B 1R6, Canada.
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Gardiner AT, Nguyen-Phan TC, Cogdell RJ. A comparative look at structural variation among RC-LH1 'Core' complexes present in anoxygenic phototrophic bacteria. Photosynth Res 2020; 145:83-96. [PMID: 32430765 PMCID: PMC7423801 DOI: 10.1007/s11120-020-00758-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/10/2020] [Indexed: 05/30/2023]
Abstract
All purple photosynthetic bacteria contain RC-LH1 'Core' complexes. The structure of this complex from Rhodobacter sphaeroides, Rhodopseudomonas palustris and Thermochromatium tepidum has been solved using X-ray crystallography. Recently, the application of single particle cryo-EM has revolutionised structural biology and the structure of the RC-LH1 'Core' complex from Blastochloris viridis has been solved using this technique, as well as the complex from the non-purple Chloroflexi species, Roseiflexus castenholzii. It is apparent that these structures are variations on a theme, although with a greater degree of structural diversity within them than previously thought. Furthermore, it has recently been discovered that the only phototrophic representative from the phylum Gemmatimonadetes, Gemmatimonas phototrophica, also contains a RC-LH1 'Core' complex. At present only a low-resolution EM-projection map exists but this shows that the Gemmatimonas phototrophica complex contains a double LH1 ring. This short review compares these different structures and looks at the functional significance of these variations from two main standpoints: energy transfer and quinone exchange.
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Affiliation(s)
- Alastair T Gardiner
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
- Laboratory of Anoxygenic Phototrophs, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradska 237, 379 01, Třeboň, Czech Republic.
| | - Tu C Nguyen-Phan
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Richard J Cogdell
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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Huang X, Vasilev C, Hunter CN. Excitation energy transfer between monomolecular layers of light harvesting LH2 and LH1-reaction centre complexes printed on a glass substrate. Lab Chip 2020; 20:2529-2538. [PMID: 32662473 DOI: 10.1039/d0lc00156b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Light-harvesting 2 (LH2) and light-harvesting 1 - reaction centre (RCLH1) complexes purified from the photosynthetic bacterium Rhodobacter (Rba.) sphaeroides were cross-patterned on glass surfaces for energy transfer studies. Atomic force microscopy (AFM) images of the RCLH1 and LH2 patterns show the deposition of monomolecular layers of complexes on the glass substrate. Spectral imaging and fluorescence life-time imaging microscopy (FLIM) revealed that RCLH1 and LH2 complexes, sealed under physiological conditions, retained their native light-harvesting and energy transfer functions. Measurements of the amplitude and lifetime decay of fluorescence emission from LH2 complexes, the energy transfer donors, and gain of fluorescence emission from acceptor RCLH1 complexes, provide evidence for excitation energy transfer from LH2 to RCLH1. Directional energy transfer on the glass substrate was unequivocally established by using LH2-carotenoid complexes and RCLH1 complexes with genetically removed carotenoids. Specific excitation of carotenoids in donor LH2 complexes elicited fluorescence emission from RCLH1 acceptors. To explore the longevity of this novel nanoprinted photosynthetic unit, RCLH1 and LH2 complexes were cross-patterned on a glass surface and sealed under a protective argon atmosphere. The results show that both complexes retained their individual and collective functions and are capable of directional excitation energy transfer for at least 60 days.
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Affiliation(s)
- Xia Huang
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
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Kang SM, Adhikari A, Lee KE, Khan MA, Khan AL, Shahzad R, Dhungana SK, Lee IJ. Inoculation with Indole-3-Acetic Acid-Producing Rhizospheric Rhodobacter sphaeroides KE149 Augments Growth of Adzuki Bean Plants Under Water Stress. J Microbiol Biotechnol 2020; 30:717-725. [PMID: 32482937 PMCID: PMC9728276 DOI: 10.4014/jmb.1911.11063] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/09/2020] [Indexed: 12/15/2022]
Abstract
The use of plant growth-promoting rhizobacteria is economically viable and environmentally safe for mitigating various plant stresses. Abiotic stresses such as flood and drought are a serious threat to present day agriculture. In the present study, the indole-3-acetic acid-producing rhizobacterium R. sphaeroides KE149 was selected, and its effect on the growth of adzuki bean plants was investigated under flood stress (FS) and drought stress (DS). IAA quantification of bacterial pure culture revealed that KE149 produced significant amount of IAA. KE149 inoculation significantly decreased stress-responsive endogenous abscisic acid and jasmonic acid and increased salicylic acid in plants under DS and FS. KE149 inoculation also increased proline under DS and methionine under FS. Moreover, KE149 inoculation significantly increased the calcium (Ca), magnesium (Mg), and potassium (K) content and lowered the sodium (Na) content in the plant shoot under stress. KE149-treated plants had significantly higher root length, shoot length, stem diameter, biomass, and chlorophyll content under both normal and stressed conditions. These results suggest that KE149 could be an efficient biofertilizer for mitigating water stress.
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Affiliation(s)
- Sang-Mo Kang
- School of Applied Biosciences, Kyungpook National University, Daegu 4566, Republic of Korea
| | - Arjun Adhikari
- School of Applied Biosciences, Kyungpook National University, Daegu 4566, Republic of Korea
| | - Ko-Eun Lee
- School of Applied Biosciences, Kyungpook National University, Daegu 4566, Republic of Korea
| | - Muhammad Aaqil Khan
- School of Applied Biosciences, Kyungpook National University, Daegu 4566, Republic of Korea
| | - Abdul Latif Khan
- Natural and Medical Science Research Center, University of Nizwa, Nizwa 616, Oman
| | - Raheem Shahzad
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Damam 1441, Saudi Arabia
- Basic and Applied Scientific Research Center, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Damam 311, Saudi Arabia
| | - Sanjeev Kumar Dhungana
- Department of Southern Area Crop Science, National Institute of Crop Science Rural Development Administration, Miryang 0424, Republic of Korea
| | - In-Jung Lee
- School of Applied Biosciences, Kyungpook National University, Daegu 4566, Republic of Korea
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Camarena L, Dreyfus G. Living in a Foster Home: The Single Subpolar Flagellum Fla1 of Rhodobacter sphaeroides. Biomolecules 2020; 10:E774. [PMID: 32429424 PMCID: PMC7277832 DOI: 10.3390/biom10050774] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 12/14/2022] Open
Abstract
Rhodobacter sphaeroides is an α-proteobacterium that has the particularity of having two functional flagellar systems used for swimming. Under the growth conditions commonly used in the laboratory, a single subpolar flagellum that traverses the cell membrane, is assembled on the surface. This flagellum has been named Fla1. Phylogenetic analyses have suggested that this flagellar genetic system was acquired from an ancient γ-proteobacterium. It has been shown that this flagellum has components homologous to those present in other γ-proteobacteria such as the H-ring characteristic of the Vibrio species. Other features of this flagellum such as a straight hook, and a prominent HAP region have been studied and the molecular basis underlying these features has been revealed. It has also been shown that FliL, and the protein MotF, mainly found in several species of the family Rhodobacteraceae, contribute to remodel the amphipathic region of MotB, known as the plug, in order to allow flagellar rotation. In the absence of the plug region of MotB, FliL and MotF are dispensable. In this review we have covered the most relevant aspects of the Fla1 flagellum of this remarkable photosynthetic bacterium.
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Affiliation(s)
- Laura Camarena
- Depto. Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, CDMX 04510, Mexico
| | - Georges Dreyfus
- Depto. Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, CDMX 04510, Mexico
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Niedzwiedzki DM, Swainsbury DJK, Hunter CN. Carotenoid-to-(bacterio)chlorophyll energy transfer in LH2 antenna complexes from Rba. sphaeroides reconstituted with non-native (bacterio)chlorophylls. Photosynth Res 2020; 144:155-169. [PMID: 31350671 PMCID: PMC7203092 DOI: 10.1007/s11120-019-00661-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/16/2019] [Indexed: 05/04/2023]
Abstract
Six variants of the LH2 antenna complex from Rba. sphaeroides, comprising the native B800-B850, B800-free LH2 (B850) and four LH2s with various (bacterio)chlorophylls reconstituted into the B800 site, have been investigated with static and time-resolved optical spectroscopies at room temperature and at 77 K. The study particularly focused on how reconstitution of a non-native (bacterio)chlorophylls affects excitation energy transfer between the naturally bound carotenoid spheroidene and artificially substituted pigments in the B800 site. Results demonstrate there is no apparent trend in the overall energy transfer rate from spheroidene to B850 bacteriochlorophyll a; however, a trend in energy transfer rate from the spheroidene S1 state to Qy of the B800 (bacterio)chlorophylls is noticeable. These outcomes were applied to test the validity of previously proposed energy values of the spheroidene S1 state, supporting a value in the vicinity of 13,400 cm-1 (746 nm).
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Affiliation(s)
- Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University, St. Louis, MO, 63130, USA.
- Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, MO, 63130, USA.
| | - David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
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Abstract
Many strategies for meeting mankind's future energy demands through the exploitation of plentiful solar energy have been influenced by the efficient and sustainable processes of natural photosynthesis. A limitation affecting solar energy conversion based on photosynthetic proteins is the selective spectral coverage that is the consequence of their particular natural pigmentation. Here we demonstrate the bottom-up formation of semisynthetic, polychromatic photosystems in mixtures of the chlorophyll-based LHCII major light harvesting complex from the oxygenic green plant Arabidopsis thaliana, the bacteriochlorophyll-based photochemical reaction center (RC) from the anoxygenic purple bacterium Rhodobacter sphaeroides and synthetic quantum dots (QDs). Polyhistidine tag adaptation of LHCII and the RC enabled predictable self-assembly of LHCII/RC/QD nanoconjugates, the thermodynamics of which could be accurately modeled and parametrized. The tricomponent biohybrid photosystems displayed enhanced solar energy conversion via either direct chlorophyll-to-bacteriochlorophyll energy transfer or an indirect pathway enabled by the QD, with an overall energy transfer efficiency comparable to that seen in natural photosystems.
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Affiliation(s)
- Juntai Liu
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
| | - Judith Mantell
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
- Wolfson Bioimaging Facility, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
| | - Michael R Jones
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
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Su YQ, Zhao YJ, Zhang WJ, Chen GC, Qin H, Qiao DR, Chen YE, Cao Y. Removal of mercury(II), lead(II) and cadmium(II) from aqueous solutions using Rhodobacter sphaeroides SC01. Chemosphere 2020; 243:125166. [PMID: 31756653 DOI: 10.1016/j.chemosphere.2019.125166] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 10/09/2019] [Accepted: 10/20/2019] [Indexed: 06/10/2023]
Abstract
Microorganisms and microbial products can be highly efficient in uptaking soluble and particulate forms of heavy metals, particularly from solutions. In this study, the removal efficiency, oxidative damage, antioxidant system, and the possible removal mechanisms were investigated in Rhodobacter (R.) sphaeroides SC01 under mercury (Hg), lead (Pb) and cadmium (Cd) stress. The results showed that SC01 had the highest removal rates (98%) of Pb among three heavy metals. Compared with Hg and Cd stress, Pb stress resulted in a lower levels of reactive oxygen species (ROS) and cell death. In contrast, the activities of four antioxidant enzymes in SC01 under Pb stress was higher than that of Hg and Cd stress. Furthermore, the analysis from fourier transform infrared spectroscopy indicated that complexation of Pb with hydroxyl, amid and phosphate groups was found in SC01 under Pb stress. In addition, X-ray diffraction analysis showed that precipitate of lead phosphate hydroxide was produced on the cell surface in SC01 exposed to Pb stress. Therefore, these results suggested that SC01 had good Pb removal ability by biosorption and precipitation and will be potentially useful for removal of Pb in industrial effluents.
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Affiliation(s)
- Yan-Qiu Su
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Yang-Juan Zhao
- College of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Wei-Jia Zhang
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Guo-Cheng Chen
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Han Qin
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Dai-Rong Qiao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China
| | - Yang-Er Chen
- College of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China.
| | - Yi Cao
- Microbiology and Metabolic Engineering of Key Laboratory of Sichuan Province, College of Life Sciences, Sichuan University, Chengdu, 610064, China.
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38
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Yoneda Y, Kato D, Kondo M, Nagashima KVP, Miyasaka H, Nagasawa Y, Dewa T. Sequential energy transfer driven by monoexponential dynamics in a biohybrid light-harvesting complex 2 (LH2). Photosynth Res 2020; 143:115-128. [PMID: 31620983 DOI: 10.1007/s11120-019-00677-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/24/2019] [Indexed: 06/10/2023]
Abstract
Enhancing the light-harvesting potential of antenna components in a system of solar energy conversion is an important topic in the field of artificial photosynthesis. We constructed a biohybrid light-harvesting complex 2 (LH2) engineered from Rhodobacter sphaeroides IL106 strain. An artificial fluorophore Alexa Fluor 647 maleimide (A647) was attached to the LH2 bearing cysteine residue at the N-terminal region (LH2-NC) near B800 bacteriochlorophyll a (BChl) assembly. The A647-attached LH2-NC conjugate (LH2-NC-A647) preserved the integrity of the intrinsic chromophores, B800- and B850-BChls, and carotenoids. Femtosecond transient absorption spectroscopy revealed that the sequential energy transfer A647 → B800 → B850 occurs at time scale of 9-10 ps with monoexponential dynamics in micellar and lipid bilayer systems. A B800-removed conjugate (LH2-NC[B800(-)]-A647) exhibited a significant decrease in energy transfer efficiency in the micellar system; however, surprisingly, direct energy transfer from A647 to B850 was observed at a rate comparable to that for LH2-NC-A647. This result implies that the energy transfer pathway is modified after B800 removal. The results obtained suggested that a LH2 complex is a potential platform for construction of biohybrid light-harvesting materials with simple energy transfer dynamics through the site-selective attachment of the external antennae and the modifiable energy-funnelling pathway.
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Affiliation(s)
- Yusuke Yoneda
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan
| | - Daiji Kato
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan
| | - Masaharu Kondo
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan
| | - Kenji V P Nagashima
- Research Institute for Integrated Science, Kanagawa University, Kanagawa, 259-1293, Japan
| | - Hiroshi Miyasaka
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan
| | - Yutaka Nagasawa
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan.
| | - Takehisa Dewa
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan.
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Espiritu E, Chamberlain KD, Williams JC, Allen JP. Bound manganese oxides capable of reducing the bacteriochlorophyll dimer of modified reaction centers from Rhodobacter sphaeroides. Photosynth Res 2020; 143:129-141. [PMID: 31641987 DOI: 10.1007/s11120-019-00680-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/09/2019] [Indexed: 06/10/2023]
Abstract
A biohybrid model system is described that interfaces synthetic Mn-oxides with bacterial reaction centers to gain knowledge concerning redox reactions by metal clusters in proteins, in particular the Mn4CaO5 cluster of photosystem II. The ability of Mn-oxides to bind to modified bacterial reaction centers and transfer an electron to the light-induced oxidized bacteriochlorophyll dimer, P+, was characterized using optical spectroscopy. The environment of P was altered to obtain a high P/P+ midpoint potential. In addition, different metal-binding sites were introduced by substitution of amino acid residues as well as extension of the C-terminus of the M subunit with the C-terminal region of the D1 subunit of photosystem II. The Mn-compounds MnO2, αMn2O3, Mn3O4, CaMn2O4, and Mn3(PO4)2 were tested and compared to MnCl2. In general, addition of the Mn-compounds resulted in a decrease in the amount of P+ while the reduced quinone was still present, demonstrating that the Mn-compounds can serve as secondary electron donors. The extent of P+ reduction for the Mn-oxides was largest for αMn2O3 and CaMn2O4 and smallest for Mn3O4 and MnO2. The addition of Mn3(PO4)2 resulted in nearly complete P+ reduction, similar to MnCl2. Overall, the activity was correlated with the initial oxidation state of the Mn-compound. Transient optical measurements showed a fast kinetic component, assigned to reduction of P+ by the Mn-oxide, in addition to a slow component due to charge recombination. The results support the conjecture that the incorporation of Mn-oxides by ancient anoxygenic phototrophs was a step in the evolution of oxygenic photosynthesis.
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Affiliation(s)
- Eduardo Espiritu
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
| | - Kori D Chamberlain
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
| | - JoAnn C Williams
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
| | - James P Allen
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA.
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Xu M, Wu H, Shen P, Jiang X, Chen X, Lin J, Huang J, Qi F. Enhancement of NADPH availability for coproduction of coenzyme Q 10 and farnesol from Rhodobacter sphaeroides. J Ind Microbiol Biotechnol 2020; 47:263-274. [PMID: 31993848 DOI: 10.1007/s10295-020-02261-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 01/14/2020] [Indexed: 12/16/2022]
Abstract
Coenzyme Q10 (CoQ10)-an essential cofactor in the respiratory electron transport chain-has important pharmaceutical and healthcare applications. Farnesol (FOH)-an acyclic sesquiterpene alcohol-has garnered interest owing to its valuable clinical and medical benefits. Here, the coproduction of CoQ10 and FOH in Rhodobacter sphaeroides GY-2 was greatly improved through the enhancement of intracellular NADPH availability. Transcription of pgi, gdhA, and nuocd was, respectively, inhibited using RNA interference to reduce intracellular NAD(P)H consumption. Moreover, zwf, gnd, and zwf + gnd were overexpressed to enhance the pentose phosphate pathway, resulting in improved NADPH availability in most metabolically engineered R. sphaeroides strains. RSg-pgi with RNAi of pgi combined with overexpression of gnd produced 55.05 mg/L FOH that is twofold higher than the parental strain GY-2, and 185.5 mg/L CoQ10 can be coproduced at the same time. In conclusion, improved carbon flux can be redirected toward NADPH-dependent biosynthesis through the enhancement of NADPH availability.
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Affiliation(s)
- Man Xu
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Hongxuan Wu
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Peijie Shen
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Xianzhang Jiang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China.
| | - Xueduan Chen
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Jinxin Lin
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China
| | - Jianzhong Huang
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China.
| | - Feng Qi
- Engineering Research Center of Industrial Microbiology of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, 350117, Fujian, China.
- Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation and Provincial University Engineering Research Center of Industrial Biocatalysis, Fujian Normal University, Fuzhou, 350117, Fujian, China.
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41
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Wu P, Chen Z, Zhang Y, Wang Y, Zhu F, Cao B, Jin L, Hou Y, Wu Y, Li N. Carbaryl waste-water treatment by Rhodopseudomonas sphaeroides. Chemosphere 2019; 233:597-602. [PMID: 31195264 DOI: 10.1016/j.chemosphere.2019.05.237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 04/09/2019] [Accepted: 05/27/2019] [Indexed: 06/09/2023]
Abstract
Carbaryl wastewater treatment and the resource recycling of biomass as sludge by Rhodopseudomonas sphaeroides (R. sphaeroides) with the assistance of starch processing wastewater (SPW) was investigated in this research. It was observed that carbaryl was not degraded under the 100, 500 mg/L COD groups. The addition of SPW assisted R. sphaeroides to degrade carbaryl efficiently. Carbaryl removal reached 100% after 5 days under the optimal group (3500 mg/L). Interestingly, carbaryl in the mixed wastewater began to be degraded after day 1. Further research indicated that cehA gene was expressed after day 1. Subsequently, carbaryl hydrolase was synthesized under gene regulation. Analysis revealed that cehA and carbaryl hydrolase were adaptive gene expressions and enzymes. Carbaryl as stimulus signal started cehA gene expression through signal transduction pathway. This process took one day for R. sphaeroides. However, organics in 100, 500 mg/L COD groups were deficient, which could not maintain R. sphaeroides growth for over one day. Organics in SPW provided sufficient carbon sources for R. sphaeroides under other groups. The method could complete the mixed (SPW and carbaryl) wastewater treatment, carbaryl removal, the resource recycling of R. sphaeroides biomass as sludge simultaneously.
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Affiliation(s)
- Pan Wu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Zhaobo Chen
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Ying Zhang
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China.
| | - Yanling Wang
- Department of Anesthesiology, The Third Affiliated Hospital of SunYat-Sen University, Guangzhou, 510630, China
| | - Feifei Zhu
- Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110164, China
| | - Bo Cao
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Liming Jin
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Yanxi Hou
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China
| | - Yuan Wu
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Ning Li
- School of Environment and Resources, Dalian Minzu University, Dalian, 116600, China; School of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
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Qiang S, Su AP, Li Y, Chen Z, Hu CY, Meng YH. Elevated β-Carotene Synthesis by the Engineered Rhodobacter sphaeroides with Enhanced CrtY Expression. J Agric Food Chem 2019; 67:9560-9568. [PMID: 31368704 DOI: 10.1021/acs.jafc.9b02597] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
β-Carotene is a precursor of vitamin A and a dietary supplement for its antioxidant property. Producing β-carotene by microbial fermentation has attracted much attention owing to consumers' preference for the natural product. In this study, an engineered photosynthetic Rhodobacter sphaeroides producing β-carotene was constructed by the following strategies: (1) five promoters of different strengths were used to investigate the effect of the expression level of crtY on β-carotene content. It was found that PrrnB increased the β-carotene content by 109%. (2) blocking of the branched pentose phosphate pathway by zwf deletion, and (3) overexpressing dxs could restore the transcriptional levels of crtE and crtB. Finally, the engineered RS-C3 has the highest β-carotene content of 14.93 mg/g dry cell weight (DCW) among all of the reported photosynthetic bacteria and the β-carotene content reached 3.34 mg/g DCW under light conditions. Our results will be available for industrial use to supply a large quantity of natural β-carotene.
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Affiliation(s)
- Shan Qiang
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
- Xi'an Healthful Biotechnology Co., Ltd. , HangTuo Road , Chang'an, Xi'an 710100 , P. R. China
| | - An Ping Su
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
| | - Ying Li
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , P. R. China
| | - Zhi Chen
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , P. R. China
| | - Ching Yuan Hu
- Human Nutrition, Food, and Animal Science , University of Hawai'i at Manoa , 1955 East-West Road, AgSci. 415J , Honolulu , Hawaii 96822-2217 , United States
| | - Yong Hong Meng
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
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Abstract
This year marks the 50th anniversary of the discovery of σ70 as a protein factor that was needed for bacterial RNA polymerase to accurately transcribe a promoter in vitro. It was 25 years later that the Group IV alternative σs were described as a distinct family of proteins related to σ70 . In the intervening time, there has been an ever-growing list of Group IV σs, numbers of genes they transcribe, insight into the diverse suite of processes they control, and appreciation for their impact on bacterial lifestyles. This work summarizes knowledge of the Rhodobacter sphaeroides σE -ChrR pair, a member of the ECF11 subfamily of Group IV alternative σs, in protecting cells from the reactive oxygen species, singlet oxygen. It describes lessons learned from analyzing ChrR, a zinc-dependent anti-σ factor, that are generally applicable to Group IV σs and relevant to the response to single oxygen. This MicroReview also illustrates insights into stress responses in this and other bacteria that have been acquired by analyzing or modeling the activity of the σE -ChrR across the bacterial phylogeny.
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Affiliation(s)
- Timothy J. Donohue
- Bacteriology Department, Great Lakes Bioenergy Research CenterWisconsin Energy Institute, University of Wisconsin‐MadisonMadisonWI53726USA
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Zhao Z, Peng T, Oh JI, Glaeser J, Weber L, Li Q, Klug G. A response regulator of the OmpR family is part of the regulatory network controlling the oxidative stress response of Rhodobacter sphaeroides. Environ Microbiol Rep 2019; 11:118-128. [PMID: 30451391 DOI: 10.1111/1758-2229.12718] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
As a free-living bacterium Rhodobacter sphaeroides needs to respond to many environmental stresses. Oxidative stress, membrane stress or heat stress induce the ompR-1 gene encoding a protein of the OmpR family. Overexpression of OmpR-1 results in increased resistance to organic peroxides and diamide. Our data demonstrate that OmpR-1 positively affects expression of several sRNAs with an established role in R. sphaeroides stress defences and negatively affects the promoter of the rpoHI gene. The RpoHI sigma factor has a main role in the activation of many stress responses. Thus OmpR-1 has a balancing effect on the activation of the RpoHI regulon. We present a model with OmpR-1 as part of a regulatory network controlling stress defences in R. sphaeroides.
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Affiliation(s)
- Zhiping Zhao
- Institut für Mikrobiologie und Molekularbiologie, Interdiziplinäres Forschungszentrum, Justus-Liebig-Universität Giessen, Giessen, Germany
- Department of Pharmaceutical Engineering, Sichuan University of Science and Engineering, Zigong, China
| | | | - Jeong-Il Oh
- Department of Microbiology, Pusan National University, Busan, South Korea
| | - Jens Glaeser
- Institut für Mikrobiologie und Molekularbiologie, Interdiziplinäres Forschungszentrum, Justus-Liebig-Universität Giessen, Giessen, Germany
| | - Lennart Weber
- Institut für Mikrobiologie und Molekularbiologie, Interdiziplinäres Forschungszentrum, Justus-Liebig-Universität Giessen, Giessen, Germany
| | - Qingfeng Li
- Institut für Mikrobiologie und Molekularbiologie, Interdiziplinäres Forschungszentrum, Justus-Liebig-Universität Giessen, Giessen, Germany
| | - Gabriele Klug
- Institut für Mikrobiologie und Molekularbiologie, Interdiziplinäres Forschungszentrum, Justus-Liebig-Universität Giessen, Giessen, Germany
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45
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Knox PP, Lukashev EP, Gorokhov VV, Seifullina NK, Paschenko VZ. Relaxation processes accompanying electron stabilization in the quinone acceptor part of Rb. sphaeroides reaction centers. J Photochem Photobiol B 2018; 189:145-151. [PMID: 30347352 DOI: 10.1016/j.jphotobiol.2018.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/03/2018] [Accepted: 10/04/2018] [Indexed: 06/08/2023]
Abstract
The temperature dependence of the dark recombination rate in photooxidized bacteriochlorophyll (P) and photoreduced quinone acceptors (ubiquinones) QA and QB of photosynthetic reaction centers of purple bacteria Rhodobacter sphaeroides (Rb. sphaeroides) was studied. Photoinduced changes in the absorption were detected in the Qx absorption band of photooxidized bacteriochlorophyll at 600 nm and in the bands corresponding to the redox changes of ubiquinones at 335 and 420-450 nm. Kinetic analysis was used to evaluate the activation energy and the characteristic time of the transient process of relaxation accompanying electron stabilization at the final quinone acceptor. A comparative study of the kinetics of oxidation-reduction reactions of photoactive bacteriochlorophyll RC purple bacteria and quinone acceptors in their individual absorption bands is an informative approach to studying the mechanisms of this stabilization. The analysis of the revealed kinetic differences makes it possible to estimate the activation energy and the characteristic times of the transition relaxation processes associated with the stabilization of the electron in the quinone acceptor part of RC. Purple bacterial reaction centers have fundamental similarities with PSII reaction centers. Such a similarity represents evolutional closeness between the two types of RC. So it is possible that the photoinduced charge separation in PSII RC, as well as in purple bacteria RC, is also accompanied by definite conformational changes. The possible role of hydrogen bonds of surrounding protein in the relaxation processes accompanying the electron transfer to quinone acceptors is discussed.
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Affiliation(s)
- P P Knox
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia
| | - E P Lukashev
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia
| | - V V Gorokhov
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia
| | - N Kh Seifullina
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia
| | - V Z Paschenko
- Department of Biophysics, Biological Faculty of the M.V., Lomonosov Moscow State University, 119991 Moscow, Russia.
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Białek R, Swainsbury DJK, Wiesner M, Jones MR, Gibasiewicz K. Modelling of the cathodic and anodic photocurrents from Rhodobacter sphaeroides reaction centres immobilized on titanium dioxide. Photosynth Res 2018; 138:103-114. [PMID: 29971571 PMCID: PMC6208573 DOI: 10.1007/s11120-018-0550-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/21/2018] [Indexed: 06/08/2023]
Abstract
As one of a number of new technologies for the harnessing of solar energy, there is interest in the development of photoelectrochemical cells based on reaction centres (RCs) from photosynthetic organisms such as the bacterium Rhodobacter (Rba.) sphaeroides. The cell architecture explored in this report is similar to that of a dye-sensitized solar cell but with delivery of electrons to a mesoporous layer of TiO2 by natural pigment-protein complexes rather than an artificial dye. Rba. sphaeroides RCs were bound to the deposited TiO2 via an engineered extramembrane peptide tag. Using TMPD (N,N,N',N'-tetramethyl-p-phenylenediamine) as an electrolyte, these biohybrid photoactive electrodes produced an output that was the net product of cathodic and anodic photocurrents. To explain the observed photocurrents, a kinetic model is proposed that includes (1) an anodic current attributed to injection of electrons from the triplet state of the RC primary electron donor (PT) to the TiO2 conduction band, (2) a cathodic current attributed to reduction of the photooxidized RC primary electron donor (P+) by surface states of the TiO2 and (3) transient cathodic and anodic current spikes due to oxidation/reduction of TMPD/TMPD+ at the conductive glass (FTO) substrate. This model explains the origin of the photocurrent spikes that appear in this system after turning illumination on or off, the reason for the appearance of net positive or negative stable photocurrents depending on experimental conditions, and the overall efficiency of the constructed cell. The model may be a used as a guide for improvement of the photocurrent efficiency of the presented system as well as, after appropriate adjustments, other biohybrid photoelectrodes.
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Affiliation(s)
- Rafał Białek
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Umultowska 85, 61-614, Poznan, Poland.
| | - David J K Swainsbury
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Maciej Wiesner
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Umultowska 85, 61-614, Poznan, Poland
- NanoBioMedical Center, Adam Mickiewicz University in Poznań, ul. Umultowska 85, 61-614, Poznan, Poland
| | - Michael R Jones
- School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Krzysztof Gibasiewicz
- Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Umultowska 85, 61-614, Poznan, Poland.
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47
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Konar A, Sechrist R, Song Y, Policht VR, Laible PD, Bocian DF, Holten D, Kirmaier C, Ogilvie JP. Electronic Interactions in the Bacterial Reaction Center Revealed by Two-Color 2D Electronic Spectroscopy. J Phys Chem Lett 2018; 9:5219-5225. [PMID: 30136848 DOI: 10.1021/acs.jpclett.8b02394] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The bacterial reaction center (BRC) serves as an important model system for understanding the charge separation processes in photosynthesis. Knowledge of the electronic structure of the BRC is critical for understanding its charge separation mechanism. While it is well-accepted that the "special pair" pigments are strongly coupled, the degree of coupling among other BRC pigments has been thought to be relatively weak. Here we study the W(M250)V mutant BRC by two-color two-dimensional electronic spectroscopy to correlate changes in the Q x region with excitation of the Q y transitions. The resulting Q y-Q x cross-peaks provide a sensitive measure of the electronic interactions throughout the BRC pigment network and complement one-color 2D studies in which such interactions are often obscured by energy transfer and excited-state absorption signals. Our observations should motivate the refinement of electronic structure models of the BRC to facilitate improved understanding of the charge separation mechanism.
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Affiliation(s)
- Arkaprabha Konar
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
| | - Riley Sechrist
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
| | - Yin Song
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
| | - Veronica R Policht
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
| | - Philip D Laible
- Biosciences Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - David F Bocian
- Department of Chemistry , University of California , Riverside , California 92521 , United States
| | - Dewey Holten
- Department of Chemistry , Washington University , St. Louis , Missouri 63130 , United States
| | - Christine Kirmaier
- Department of Chemistry , Washington University , St. Louis , Missouri 63130 , United States
| | - Jennifer P Ogilvie
- Department of Physics , University of Michigan , Ann Arbor , Michigan 49109-1040 , United States
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48
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Liu S, Zheng Z, Tie J, Kang J, Zhang G, Zhang J. Impacts of Fe 2+ on 5-aminolevulinic acid (ALA) biosynthesis of Rhodobacter sphaeroides in wastewater treatment by regulating nif gene expression. J Environ Sci (China) 2018; 70:11-19. [PMID: 30037398 DOI: 10.1016/j.jes.2017.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/02/2017] [Accepted: 11/02/2017] [Indexed: 06/08/2023]
Abstract
This study aimed to increase bacterial growth and 5-aminolevulinic acid (ALA) biosynthesis of Rhodobacter sphaeroides in wastewater treatment through adding ferrous ion (Fe2+). Results demonstrated that Fe2+ effectively enhanced the biomass production and ALA yield of R. sphaeroides. Moreover, the optimal Fe2+ dosage was found to be 400μmol/L, which was associated with the highest biomass of 4015.3mg/L and maximum ALA yield of 15.9mg/g-dry cell weight (mg/g-DCW). Mechanism analysis revealed that Fe2+ vastly improved Adenosine Triphosphate (ATP) production by up-regulating the nif gene expression, and increasing ATP enhanced the biomass and ALA yield by supplying energy for bacterial growth and ALA biosynthesis, respectively. Correlation analysis showed that the ALA and ATP yields had positive relation with nifA and nifU gene expression. In addition, the nifA and nifU gene expression displayed high consistency of co-transcription at the optimal Fe2+ dosage.
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Affiliation(s)
- Shuli Liu
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450000, China; Henan Key Laboratory of Water Environment Simulation and Treatment, Zhengzhou 450046, China; Henan Engineering Research Center of Water Pollution and Soil Damage Remediation, Zhengzhou 450046, China.
| | - Zhihong Zheng
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450000, China; Henan Key Laboratory of Water Environment Simulation and Treatment, Zhengzhou 450046, China; Henan Engineering Research Center of Water Pollution and Soil Damage Remediation, Zhengzhou 450046, China
| | - Jingxi Tie
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450000, China; Henan Key Laboratory of Water Environment Simulation and Treatment, Zhengzhou 450046, China; Henan Engineering Research Center of Water Pollution and Soil Damage Remediation, Zhengzhou 450046, China
| | - Jia Kang
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450000, China; Henan Key Laboratory of Water Environment Simulation and Treatment, Zhengzhou 450046, China; Henan Engineering Research Center of Water Pollution and Soil Damage Remediation, Zhengzhou 450046, China
| | - Guangming Zhang
- School of Environment and Resource, Renmin University of China, Beijing 100872, China
| | - Jie Zhang
- School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
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49
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Liu Y, Esyunina D, Olovnikov I, Teplova M, Kulbachinskiy A, Aravin AA, Patel DJ. Accommodation of Helical Imperfections in Rhodobacter sphaeroides Argonaute Ternary Complexes with Guide RNA and Target DNA. Cell Rep 2018; 24:453-462. [PMID: 29996105 PMCID: PMC6269105 DOI: 10.1016/j.celrep.2018.06.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 04/11/2018] [Accepted: 06/05/2018] [Indexed: 12/12/2022] Open
Abstract
Prokaryotic Argonaute (Ago) proteins were recently shown to target foreign genetic elements, thus making them a perfect model for studies of interference mechanisms. Here, we study interactions of Rhodobacter sphaeroides Ago (RsAgo) with guide RNA (gRNA) and fully complementary or imperfect target DNA (tDNA) using biochemical and structural approaches. We show that RsAgo can specifically recognize both the first nucleotide in gRNA and complementary nucleotide in tDNA, and both interactions contribute to nucleic acid binding. Non-canonical pairs and bulges on the target strand can be accommodated by RsAgo with minimal perturbation of the duplex but significantly reduce RsAgo affinity to tDNA. Surprisingly, mismatches between gRNA and tDNA induce dissociation of the guide-target duplex from RsAgo. Our results reveal plasticity in the ability of Ago proteins to accommodate helical imperfections, show how this might affect the efficiency of RNA silencing, and suggest a potential mechanism for guide release and Ago recycling.
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Affiliation(s)
- Yiwei Liu
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Daria Esyunina
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia
| | - Ivan Olovnikov
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Marianna Teplova
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Andrey Kulbachinskiy
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia.
| | - Alexei A Aravin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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50
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Tan LM, Yu J, Kawakami T, Kobayashi M, Wang P, Wang-Otomo ZY, Zhang JP. New Insights into the Mechanism of Uphill Excitation Energy Transfer from Core Antenna to Reaction Center in Purple Photosynthetic Bacteria. J Phys Chem Lett 2018; 9:3278-3284. [PMID: 29863354 DOI: 10.1021/acs.jpclett.8b01197] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The uphill excitation energy transfer (EET) from the core antenna (LH1) to the reaction center (RC) of purple photosynthetic bacteria was investigated at room temperature by comparing the native LH1-RC from Thermochromatium ( Tch.) tepidum with the hybrid LH1-RC from a mutant strain of Rhodobacter ( Rba.) sphaeroides. The latter protein with chimeric Tch-LH1 and Rba-RC exhibits a substantially larger RC-to-LH1 energy difference (Δ E = 630 cm-1) of 3-fold thermal energy (3 kB T). The spectroscopic and kinetics results are discussed on the basis of the newly reported high-resolution structures of Tch. tepidum LH1-RC, which allow us to propose the existence of a passage formed by LH1 BChls that facilitates the LH1 → RC EET. The semilogarithmic plot of the EET rate against Δ E was found to be linear over a broad range of Δ E, which consolidates the mechanism of thermal activation as promoted by the spectral overlap between the LH1 fluorescence and the special pair absorption of RC.
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Affiliation(s)
- Li-Ming Tan
- Department of Chemistry , Renmin University of China , Beijing 1000872 , PR China
| | - Jie Yu
- Department of Chemistry , Renmin University of China , Beijing 1000872 , PR China
| | | | - Masayuki Kobayashi
- Institute of National Colleges of Technology , Ariake College , Omuta , Fukuoka 836-8585 , Japan
| | - Peng Wang
- Department of Chemistry , Renmin University of China , Beijing 1000872 , PR China
| | | | - Jian-Ping Zhang
- Department of Chemistry , Renmin University of China , Beijing 1000872 , PR China
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