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Madhu S, Sengupta A, Sarnaik AP, Wangikar PP. Expanding the synthetic biology repertoire of a fast-growing cyanobacterium Synechococcus elongatus PCC 11801. Biotechnol Bioeng 2024. [PMID: 38773863 DOI: 10.1002/bit.28740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 05/04/2024] [Accepted: 05/07/2024] [Indexed: 05/24/2024]
Abstract
Synechococcus elongatus PCC 11801 is a fast-growing cyanobacterium, exhibiting high tolerance to environmental stresses. We have earlier characterized its genome and analysed its transcriptome and proteome. However, to deploy it as a potential cell factory, it is necessary to expand its synthetic biology toolbox, including promoter elements and ribosome binding sites (RBSs). Here, based on the global transcriptome analysis, 48 native promoters of the genes with high transcript count were characterized using a fluorescent reporter system. The promoters PcpcB, PpsbA1, and P11770 exhibited consistently high fluorescence under all the cultivation conditions. Similarly, from the genome data and proteome analysis, 534 operons were identified. Fifteen intergenic regions exhibiting higher protein expression from the downstream gene were systematically characterized for identifying RBSs, using an operon construct comprising fluorescent protein genes eyfp and mTurq under PcpcB (PcpcB:eyfp:RBS:mTurq:TrrnB). Overall, the work presents promoter and RBS sequence libraries, with varying strengths, to expedite bioengineering of PCC 11801.
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Affiliation(s)
- Swati Madhu
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Annesha Sengupta
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Aditya P Sarnaik
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Pramod P Wangikar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
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2
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Chen Z, Shi C, Liu A. Toxicity of urban stormwater on Chlorella pyrenoidosa: Implications for reuse safety. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171803. [PMID: 38508264 DOI: 10.1016/j.scitotenv.2024.171803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 03/13/2024] [Accepted: 03/16/2024] [Indexed: 03/22/2024]
Abstract
Urban stormwater is an alternative water source used to mitigate water resource shortages, and ensuring the safety of stormwater reuse is essential. An in-depth understanding of both individual pollutant concentrations/loads in stormwater and holistic stormwater quality can be used to comprehensively evaluate how safely stormwater can be reused. The toxicity test takes all pollutants present in water samples into account, and the results reflect the integrated effect of these pollutants. In this study, the influence of urban stormwater sourced from different land uses on microalgae (Chlorella pyrenoidosa) and the possible toxicity mechanisms were investigated. The results showed that urban stormwater, particularly residential road stormwater, significantly inhibited microalgal growth. The chlorophyll contents of microalgae exposed to residential road stormwater were relatively lower, while the corresponding values were relatively higher for microalgae exposed to grassland road stormwater. Additionally, the antioxidant-related metabolism of microalgae could be dysregulated due to exposure to urban stormwater. A possible toxicity mechanism is that urban stormwater influences metabolic pathways related to chlorophyll synthesis and further hinders photosynthesis and hence microalgal growth. To resist oxidative stress and maintain regular microalgal cell activities, the ribosome metabolism pathway was upregulated. The research results contribute to elucidating the toxicity effects of urban stormwater and hence provide useful insight for ensuring the safety of stormwater reuse. It is also worth noting that the study outcomes can only represent the influence of land use on stormwater toxicity, while the impacts of other factors (particularly rainfall-runoff characteristics) have not been considered. Therefore, the consideration of all influential factors of stormwater is strongly recommended to generate more robust results in the future and provide more effective guidance for real practices related to stormwater reuse safety.
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Affiliation(s)
- Zhifeng Chen
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
| | - Chenhao Shi
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
| | - An Liu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
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3
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Ślesak I, Ślesak H. From cyanobacteria and cyanophages to chloroplasts: the fate of the genomes of oxyphototrophs and the genes encoding photosystem II proteins. THE NEW PHYTOLOGIST 2024; 242:1055-1067. [PMID: 38439684 DOI: 10.1111/nph.19633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/02/2024] [Indexed: 03/06/2024]
Abstract
Chloroplasts are the result of endosymbiosis of cyanobacterial organisms with proto-eukaryotes. The psbA, psbD and psbO genes are present in all oxyphototrophs and encode the D1/D2 proteins of photosystem II (PSII) and PsbO, respectively. PsbO is a peripheral protein that stabilizes the O2-evolving complex in PSII. Of these genes, psbA and psbD remained in the chloroplastic genome, while psbO was transferred to the nucleus. The genomes of selected cyanobacteria, chloroplasts and cyanophages carrying psbA and psbD, respectively, were analysed. The highest density of genes and coding sequences (CDSs) was estimated for the genomes of cyanophages, cyanobacteria and chloroplasts. The synonymous mutation rate (rS) of psbA and psbD in chloroplasts remained almost unchanged and is lower than that of psbO. The results indicate that the decreasing genome size in chloroplasts is more similar to the genome reduction observed in contemporary endosymbiotic organisms than in streamlined genomes of free-living cyanobacteria. The rS of atpA, which encodes the α-subunit of ATP synthase in chloroplasts, suggests that psbA and psbD, and to a lesser extent psbO, are ancient and conservative and arose early in the evolution of oxygenic photosynthesis. The role of cyanophages in the evolution of oxyphototrophs and chloroplastic genomes is discussed.
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Affiliation(s)
- Ireneusz Ślesak
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Kraków, Poland
| | - Halina Ślesak
- Institute of Botany, Faculty of Biology, Jagiellonian University, Gronostajowa 3, 30-387, Kraków, Poland
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Gates C, Ananyev G, Foflonker F, Bhattacharya D, Dismukes GC. Exceptional Quantum Efficiency Powers Biomass Production in Halotolerant Algae Picochlorum sp. . PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-024-01075-9. [PMID: 38329705 DOI: 10.1007/s11120-024-01075-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Accepted: 01/04/2024] [Indexed: 02/09/2024]
Abstract
The green algal genus Picochlorum is of biotechnological interest because of its robust response to multiple environmental stresses. We compared the metabolic performance of P. SE3 and P. oklahomense to diverse microbial phototrophs and observed exceptional performance of photosystem II (PSII) in light energy conversion in both Picochlorum species. The quantum yield (QY) for O2 evolution is the highest of any phototroph yet observed, 32% (20%) by P. SE3 (P. okl) when normalized to total PSII subunit PsbA (D1) protein, and 80% (75%) normalized per active PSII, respectively. Three factors contribute: (1) an efficient water oxidizing complex (WOC) with the fewest photochemical misses of any organism; (2) faster reoxidation of reduced (PQH2)B in P. SE3 than in P. okl. (period-2 Fourier amplitude); and (3) rapid reoxidation of the plastoquinol pool by downstream electron carriers (Cyt b6f/PETC) that regenerates PQ faster in P. SE3. This performance gain is achieved without significant residue changes around the QB site and thus points to a pull mechanism involving faster PQH2 reoxidation by Cyt b6f/PETC that offsets charge recombination. This high flux in P. SE3 may be explained by genomically encoded plastoquinol terminal oxidases 1 and 2, whereas P. oklahomense has neither. Our results suggest two distinct types of PSII centers exist, one specializing in linear electron flow and the other in PSII-cyclic electron flow. Several amino acids within D1 differ from those in the low-light-descended D1 sequences conserved in Viridiplantae, and more closely match those in cyanobacterial high-light D1 isoforms, including changes near tyrosine Yz and a water/proton channel near the WOC. These residue changes may contribute to the exceptional performance of Picochlorum at high-light intensities by increasing the water oxidation efficiency and the electron/proton flux through the PSII acceptors (QAQB).
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Affiliation(s)
- Colin Gates
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Computational Biology and Molecular Biophysics Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, 60660, USA
| | - Gennady Ananyev
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
| | - Fatima Foflonker
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
- Department of Biological Sciences, Clark Atlanta University, Atlanta, GA, 30314, USA
| | - Debashish Bhattacharya
- Department of Computational Biology and Molecular Biophysics Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA
| | - G Charles Dismukes
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA.
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08854, USA.
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5
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Cha Y, Kim W, Park Y, Kim M, Son Y, Park W. Antagonistic actions of Paucibacter aquatile B51 and its lasso peptide paucinodin toward cyanobacterial bloom-forming Microcystis aeruginosa PCC7806. JOURNAL OF PHYCOLOGY 2024; 60:152-169. [PMID: 38073162 DOI: 10.1111/jpy.13412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 10/04/2023] [Accepted: 11/08/2023] [Indexed: 02/17/2024]
Abstract
Superior antagonistic activity against axenic Microcystis aeruginosa PCC7806 was observed with Paucibacter sp. B51 isolated from cyanobacterial bloom samples among 43 tested freshwater bacterial species. Complete genome sequencing, analyzing average nucleotide identity and digital DNA-DNA hybridization, designated the B51 strain as Paucibacter aquatile. Electron and fluorescence microscopic image analyses revealed the presence of the B51 strain in the vicinity of M. aeruginosa cells, which might provoke direct inhibition of the photosynthetic activity of the PCC7806 cells, leading to perturbation of cellular metabolisms and consequent cell death. Our speculation was supported by the findings that growth failure of the PCC7806 cells led to low pH conditions with fewer chlorophylls and down-regulation of photosystem genes (e.g., psbD and psaB) during their 48-h co-culture condition. Interestingly, the concentrated ethyl acetate extracts obtained from B51-grown supernatant exhibited a growth-inhibitory effect on PCC7806. The physical separation of both strains by a filter system led to no inhibitory activity of the B51 cells, suggesting that contact-mediated anti-cyanobacterial compounds might also be responsible for hampering the growth of the PCC7806 cells. Bioinformatic tools identified 12 gene clusters that possibly produce secondary metabolites, including a class II lasso peptide in the B51 genome. Further chemical analysis demonstrated anti-cyanobacterial activity from fractionated samples having a rubrivinodin-like lasso peptide, named paucinodin. Taken together, both contact-mediated inhibition of photosynthesis and the lasso peptide secretion of the B51 strain are responsible for the anti-cyanobacterial activity of P. aquatile B51.
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Affiliation(s)
- Yeji Cha
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Wonjae Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Yerim Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Minkyung Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Yongjun Son
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Republic of Korea
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Chen Z, Huang Y, Shen Y, Zhang J, Deng J, Chen X. Denitrification shifted autotroph-heterotroph interactions in Microcystis aggregates. ENVIRONMENTAL RESEARCH 2023; 231:116269. [PMID: 37257745 DOI: 10.1016/j.envres.2023.116269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/13/2023] [Accepted: 05/27/2023] [Indexed: 06/02/2023]
Abstract
Denitrification is the most important process for nitrogen removal in eutrophic lakes and was mostly investigated in lake sediment. Denitrification could also be mediated by cyanobacterial aggregates, yet how this process impacts nitrogen (N) availability and the associated autotroph-heterotroph relationships within cyanobacterial aggregates has not been investigated. In this study, incubation experiments with nitrate amendment were conducted with Microcystis aggregates (MAs). Measurement of nitrogen contents, 16S rRNA-based microbial community profiling and metatranscriptomic sequencing were used to jointly assess nitrogen turnover dynamics, as well as changes in microbial composition and gene expression. Strong denitrification potential was revealed, and maximal N removal was achieved within two days, after which the communities entered a state of severe N limitation. Changes of active microbial communities were further promoted both with regard to taxonomic composition and transcriptive activities. Expression of transportation-related genes confirmed competition for N sources by Microcystis and phycospheric communities. Strong stress response to reactive oxygen species by Microcystis was revealed. Notably, interspecific relationships among Microcystis and phycospheric communities exhibited a shift toward antagonistic interactions, particularly evidenced by overall increased expression of genes related to cell lysis and utilization of cellular materials. Patterns of fatty acid and starch metabolism also suggested changes in carbon metabolism and cross-feeding patterns within MAs. Taken together, this study demonstrated substantial denitrification potential of MAs, which, importantly, further induced changes in both metabolic activities and autotroph-heterotroph interactions. These findings also highlight the key role of nutrient condition in shaping autotroph-heterotroph relationships.
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Affiliation(s)
- Zhijie Chen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Yingying Huang
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, Shanghai, China.
| | - Yingshi Shen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Junyi Zhang
- Jiangsu Wuxi Environmental Monitoring Center, Jiangsu, China
| | - Jie Deng
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, Shanghai, China.
| | - Xuechu Chen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restorations, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, Shanghai, China
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7
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Kwok ACM, Leung SK, Wong JTY. DNA:RNA Hybrids Are Major Dinoflagellate Minicircle Molecular Types. Int J Mol Sci 2023; 24:ijms24119651. [PMID: 37298602 DOI: 10.3390/ijms24119651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Peridinin-containing dinoflagellate plastomes are predominantly encoded in nuclear genomes, with less than 20 essential chloroplast proteins carried on "minicircles". Each minicircle generally carries one gene and a short non-coding region (NCR) with a median length of approximately 400-1000 bp. We report here differential nuclease sensitivity and two-dimensional southern blot patterns, suggesting that dsDNA minicircles are in fact the minor forms, with substantial DNA:RNA hybrids (DRHs). Additionally, we observed large molecular weight intermediates, cell-lysate-dependent NCR secondary structures, multiple bidirectional predicted ssDNA structures, and different southern blot patterns when probed with different NCR fragments. In silico analysis suggested the existence of substantial secondary structures with inverted repeats (IR) and palindrome structures within the initial ~650 bp of the NCR sequences, in accordance with conversion event(s) outcomes with PCR. Based on these findings, we propose a new transcription-templating-translation model, which is associated with cross-hopping shift intermediates. Since dinoflagellate chloroplasts are cytosolic and lack nuclear envelope breakdown, the dynamic DRH minicircle transport could have contributed to the spatial-temporal dynamics required for photosystem repair. This represents a paradigm shift from the previous understanding of "minicircle DNAs" to a "working plastome", which will have significant implications for its molecular functionality and evolution.
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Affiliation(s)
- Alvin Chun Man Kwok
- Division of Life Science, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Siu Kai Leung
- Division of Life Science, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
| | - Joseph Tin Yum Wong
- Division of Life Science, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China
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Boussac A, Sellés J, Sugiura M. Energetics and proton release in photosystem II from Thermosynechococcus elongatus with a D1 protein encoded by either the psbA 2 or psbA 3 gene. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148979. [PMID: 37080330 DOI: 10.1016/j.bbabio.2023.148979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 04/22/2023]
Abstract
In the cyanobacterium Thermosynechococcus elongatus, there are three psbA genes coding for the Photosystem II (PSII) D1 subunit that interacts with most of the main cofactors involved in the electron transfers. Recently, the 3D crystal structures of both PsbA2-PSII and PsbA3-PSII have been solved [Nakajima et al., J. Biol. Chem. 298 (2022) 102668.]. It was proposed that the loss of one hydrogen bond of PheD1 due to the D1-Y147F exchange in PsbA2-PSII resulted in a more negative Em of PheD1 in PsbA2-PSII when compared to PsbA3-PSII. In addition, the loss of two water molecules in the Cl-1 channel was attributed to the D1-P173M substitution in PsbA2-PSII. This exchange, by narrowing the Cl-1 proton channel, could be at the origin of a slowing down of the proton release. Here, we have continued the characterization of PsbA2-PSII by measuring the thermoluminescence from the S2QA-/DCMU charge recombination and by measuring proton release kinetics using time-resolved absorption changes of the dye bromocresol purple. It was found that i) the Em of PheD1-•/PheD1 was decreased by ~30 mV in PsbA2-PSII when compared to PsbA3-PSII and ii) the kinetics of the proton release into the bulk was significantly slowed down in PsbA2-PSII in the S2TyrZ• to S3TyrZ and S3TyrZ• → (S3TyrZ•)' transitions. This slowing down was partially reversed by the PsbA2/M173P mutation and induced by the PsbA3/P173M mutation thus confirming a role of the D1-173 residue in the egress of protons trough the Cl-1 channel.
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Affiliation(s)
- Alain Boussac
- I2BC, UMR CNRS 9198, CEA Saclay, 91191 Gif-sur-Yvette, France.
| | - Julien Sellés
- Institut de Biologie Physico-Chimique, UMR CNRS 7141 and Sorbonne Université, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Miwa Sugiura
- Proteo-Science Research Center, and Department of Chemistry, Graduate School of Science and Technology, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
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9
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Niedzwiedzki DM, Magdaong NCM, Su X, Adir N, Keren N, Liu H. Mass spectrometry and spectroscopic characterization of a tetrameric photosystem I supercomplex from Leptolyngbya ohadii, a desiccation-tolerant cyanobacterium. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148955. [PMID: 36708912 DOI: 10.1016/j.bbabio.2023.148955] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/06/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023]
Abstract
Cyanobacteria inhabiting desert biological soil crusts face the harsh conditions of the desert. They evolved a suite of strategies toward desiccation-hydration cycles mixed with high light irradiations, etc. In this study we purified and characterized the structure and function of Photosystem I (PSI) from Leptolyngbya ohadii, a desiccation-tolerant desert cyanobacterium. We discovered that PSI forms tetrameric (PSI-Tet) aggregate. We investigated it by using sucrose density gradient centrifugation, clear native PAGE, high performance liquid chromatography, mass spectrometry (MS), time-resolved fluorescence (TRF) and time-resolved transient absorption (TA) spectroscopy. MS analysis identified the presence of two PsaB and two PsaL proteins in PSI-Tet and uniquely revealed that PsaLs are N-terminally acetylated in contrast to non-modified PsaL in the trimeric PSI from Synechocystis sp. PCC 6803. Chlorophyll (Chl) a fluorescence decay profiles of the PSI-Tet performed at 77 K revealed two emission bands at ∼690 nm and 725 nm with the former appearing only at early delay time. The main fluorescence emission peak, associated with emission from the low energy Chls a, decays within a few nanoseconds. TA studies demonstrated that the 725 nm emission band is associated with low energy Chls a with absorption band clearly resolved at ∼710 nm at 77 K. In summary, our work suggests that the heterogenous composition of PsaBs and PsaL in PSI-Tet is related with the adaptation mechanisms needed to cope with stressful conditions under which this bacterium naturally grows.
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Affiliation(s)
- Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University in St. Louis, St. Louis, MO 63130, USA; Department of Energy Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
| | | | - Xinyang Su
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Noam Adir
- Schulich Faculty of Chemistry, Technion, Israel Institute of Technology, Hafai, Israel
| | - Nir Keren
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
| | - Haijun Liu
- Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
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Nakajima Y, Ugai-Amo N, Tone N, Nakagawa A, Iwai M, Ikeuchi M, Sugiura M, Suga M, Shen JR. Crystal structures of photosystem II from a cyanobacterium expressing psbA 2 in comparison to psbA 3 reveal differences in the D1 subunit. J Biol Chem 2022; 298:102668. [PMID: 36334624 PMCID: PMC9709244 DOI: 10.1016/j.jbc.2022.102668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/27/2022] [Accepted: 10/30/2022] [Indexed: 11/07/2022] Open
Abstract
Three psbA genes (psbA1, psbA2, and psbA3) encoding the D1 subunit of photosystem II (PSII) are present in the thermophilic cyanobacterium Thermosynechococcus elongatus and are expressed differently in response to changes in the growth environment. To clarify the functional differences of the D1 protein expressed from these psbA genes, PSII dimers from two strains, each expressing only one psbA gene (psbA2 or psbA3), were crystallized, and we analyzed their structures at resolutions comparable to previously studied PsbA1-PSII. Our results showed that the hydrogen bond between pheophytin/D1 (PheoD1) and D1-130 became stronger in PsbA2- and PsbA3-PSII due to change of Gln to Glu, which partially explains the increase in the redox potential of PheoD1 observed in PsbA3. In PsbA2, one hydrogen bond was lost in PheoD1 due to the change of D1-Y147F, which may explain the decrease in stability of PheoD1 in PsbA2. Two water molecules in the Cl-1 channel were lost in PsbA2 due to the change of D1-P173M, leading to the narrowing of the channel, which may explain the lower efficiency of the S-state transition beyond S2 in PsbA2-PSII. In PsbA3-PSII, a hydrogen bond between D1-Ser270 and a sulfoquinovosyl-diacylglycerol molecule near QB disappeared due to the change of D1-Ser270 in PsbA1 and PsbA2 to D1-Ala270. This may result in an easier exchange of bound QB with free plastoquinone, hence an enhancement of oxygen evolution in PsbA3-PSII due to its high QB exchange efficiency. These results provide a structural basis for further functional examination of the three PsbA variants.
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Affiliation(s)
- Yoshiki Nakajima
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, Japan
| | - Natsumi Ugai-Amo
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Naoki Tone
- Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Akiko Nakagawa
- Proteo-Science Research Center, Ehime University, Matsuyama, Japan
| | - Masako Iwai
- Graduate School and College of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Masahiko Ikeuchi
- Graduate School and College of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Miwa Sugiura
- Proteo-Science Research Center, Ehime University, Matsuyama, Japan
| | - Michihiro Suga
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, Japan,Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan,For correspondence: Michihiro Suga; Jian-Ren Shen
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, Japan,Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan,For correspondence: Michihiro Suga; Jian-Ren Shen
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11
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Nirati Y, Purushotham N, Alagesan S. Quantitative insight into the metabolism of isoprene-producing Synechocystis sp. PCC 6803 using steady state 13C-MFA. PHOTOSYNTHESIS RESEARCH 2022; 154:195-206. [PMID: 36070060 DOI: 10.1007/s11120-022-00957-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
Cyanobacteria are photosynthetic bacteria, widely studied for the conversion of atmospheric carbon dioxide to useful platform chemicals. Isoprene is one such industrially important chemical, primarily used for production of synthetic rubber and biofuels. Synechocystis sp. PCC 6803, a genetically amenable cyanobacterium, produces isoprene on heterologous expression of isoprene synthase gene, albeit in very low quantities. Rationalized metabolic engineering to re-route the carbon flux for enhanced isoprene production requires in-dept knowledge of the metabolic flux distribution in the cell. Hence, in the present study, we undertook steady state 13C-metabolic flux analysis of glucose-tolerant wild-type (GTN) and isoprene-producing recombinant (ISP) Synechocystis sp. to understand and compare the carbon flux distribution in the two strains. The R-values for amino acids, flux analysis predictions and gene expression profiles emphasized predominance of Calvin cycle and glycogen metabolism in GTN. Alternatively, flux analysis predicted higher activity of the anaplerotic pathway through phosphoenolpyruvate carboxylase and malic enzyme in ISP. The striking difference in the Calvin cycle, glycogen metabolism and anaplerotic pathway activity in GTN and ISP suggested a possible role of energy molecules (ATP and NADPH) in regulating the carbon flux distribution in GTN and ISP. This claim was further supported by the transcript level of selected genes of the electron transport chain. This study provides the first quantitative insight into the carbon flux distribution of isoprene-producing cyanobacterium, information critical for developing Synechocystis sp. as a single cell factory for isoprenoid/terpenoid production.
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Affiliation(s)
- Yasha Nirati
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, 560100, India
| | - Nidhish Purushotham
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, 560100, India
- Dayananda Sagar University, Bengaluru, India
| | - Swathi Alagesan
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, 560100, India.
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12
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Temperature and Geographic Location Impact the Distribution and Diversity of Photoautotrophic Gene Variants in Alkaline Yellowstone Hot Springs. Microbiol Spectr 2022; 10:e0146521. [PMID: 35575591 PMCID: PMC9241655 DOI: 10.1128/spectrum.01465-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Alkaline hot springs in Yellowstone National Park (YNP) provide a framework to study the relationship between photoautotrophs and temperature. Previous work has focused on studying how cyanobacteria (oxygenic phototrophs) vary with temperature, sulfide, and pH, but many questions remain regarding the ecophysiology of anoxygenic photosynthesis due to the taxonomic and metabolic diversity of these taxa. To this end, we examined the distribution of genes involved in phototrophy, carbon fixation, and nitrogen fixation in eight alkaline (pH 7.3-9.4) hot spring sites near the upper temperature limit of photosynthesis (71ºC) in YNP using metagenome sequencing. Based on genes encoding key reaction center proteins, geographic isolation plays a larger role than temperature in selecting for distinct phototrophic Chloroflexi, while genes typically associated with autotrophy in anoxygenic phototrophs, did not have distinct distributions with temperature. Additionally, we recovered Calvin cycle gene variants associated with Chloroflexi, an alternative carbon fixation pathway in anoxygenic photoautotrophs. Lastly, we recovered several abundant nitrogen fixation gene sequences associated with Roseiflexus, providing further evidence that genes involved in nitrogen fixation in Chloroflexi are more common than previously assumed. Together, our results add to the body of work on the distribution and functional potential of phototrophic bacteria in Yellowstone National Park hot springs and support the hypothesis that a combination of abiotic and biotic factors impact the distribution of phototrophic bacteria in hot springs. Future studies of isolates and metagenome assembled genomes (MAGs) from these data and others will further our understanding of the ecology and evolution of hot spring anoxygenic phototrophs. IMPORTANCE Photosynthetic bacteria in hot springs are of great importance to both microbial evolution and ecology. While a large body of work has focused on oxygenic photosynthesis in cyanobacteria in Mushroom and Octopus Springs in Yellowstone National Park, many questions remain regarding the metabolic potential and ecology of hot spring anoxygenic phototrophs. Anoxygenic phototrophs are metabolically and taxonomically diverse, and further investigations into their physiology will lead to a deeper understanding of microbial evolution and ecology of these taxa. Here, we have quantified the distribution of key genes involved in carbon and nitrogen metabolism in both oxygenic and anoxygenic phototrophs. Our results suggest that temperature >68ºC selects for distinct groups of cyanobacteria and that carbon fixation pathways associated with these taxa are likely subject to the same selective pressure. Additionally, our data suggest that phototrophic Chloroflexi genes and carbon fixation genes are largely influenced by local conditions as evidenced by our gene variant analysis. Lastly, we recovered several genes associated with potentially novel phototrophic Chloroflexi. Together, our results add to the body of work on hot springs in Yellowstone National Park and set the stage for future work on metagenome assembled genomes.
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Boussac A, Sellés J, Hamon M, Sugiura M. Properties of Photosystem II lacking the PsbJ subunit. PHOTOSYNTHESIS RESEARCH 2022; 152:347-361. [PMID: 34661808 DOI: 10.1007/s11120-021-00880-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/30/2021] [Indexed: 06/13/2023]
Abstract
Photosystem II (PSII), the oxygen-evolving enzyme, consists of 17 trans-membrane and 3 extrinsic membrane proteins. Other subunits bind to PSII during assembly, like Psb27, Psb28, and Tsl0063. The presence of Psb27 has been proposed (Zabret et al. in Nat Plants 7:524-538, 2021; Huang et al. Proc Natl Acad Sci USA 118:e2018053118, 2021; Xiao et al. in Nat Plants 7:1132-1142, 2021) to prevent the binding of PsbJ, a single transmembrane α-helix close to the quinone QB binding site. Consequently, a PSII rid of Psb27, Psb28, and Tsl0034 prior to the binding of PsbJ would logically correspond to an assembly intermediate. The present work describes experiments aiming at further characterizing such a ∆PsbJ-PSII, purified from the thermophilic Thermosynechococcus elongatus, by means of MALDI-TOF spectroscopy, thermoluminescence, EPR spectroscopy, and UV-visible time-resolved spectroscopy. In the purified ∆PsbJ-PSII, an active Mn4CaO5 cluster is present in 60-70% of the centers. In these centers, although the forward electron transfer seems not affected, the Em of the QB/QB- couple increases by ≥ 120 mV , thus disfavoring the electron coming back on QA. The increase of the energy gap between QA/QA- and QB/QB- could contribute in a protection against the charge recombination between the donor side and QB-, identified at the origin of photoinhibition under low light (Keren et al. in Proc Natl Acad Sci USA 94:1579-1584, 1997), and possibly during the slow photoactivation process.
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Affiliation(s)
- Alain Boussac
- I2BC, UMR CNRS 9198, CEA Saclay, 91191, Gif-sur-Yvette, France.
| | - Julien Sellés
- Institut de Biologie Physico-Chimique, UMR CNRS 7141 and Sorbonne Université, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Marion Hamon
- Institut de Biologie Physico-Chimique, UMR8226/FRC550 CNRS and Sorbonne-Université, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Miwa Sugiura
- Proteo-Science Research Center, and Department of Chemistry, Graduate School of Science and Technology, Ehime University, Bunkyo-cho, Matsuyama, Ehime, 790-8577, Japan.
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Omics-Inferred Partitioning and Expression of Diverse Biogeochemical Functions in a Low-O 2 Cyanobacterial Mat Community. mSystems 2021; 6:e0104221. [PMID: 34874776 PMCID: PMC8651085 DOI: 10.1128/msystems.01042-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyanobacterial mats profoundly influenced Earth’s biological and geochemical evolution and still play important ecological roles in the modern world. However, the biogeochemical functioning of cyanobacterial mats under persistent low-O2 conditions, which dominated their evolutionary history, is not well understood. To investigate how different metabolic and biogeochemical functions are partitioned among community members, we conducted metagenomics and metatranscriptomics on cyanobacterial mats in the low-O2, sulfidic Middle Island sinkhole (MIS) in Lake Huron. Metagenomic assembly and binning yielded 144 draft metagenome assembled genomes, including 61 of medium quality or better, and the dominant cyanobacteria and numerous Proteobacteria involved in sulfur cycling. Strains of a Phormidium autumnale-like cyanobacterium dominated the metagenome and metatranscriptome. Transcripts for the photosynthetic reaction core genes psaA and psbA were abundant in both day and night. Multiple types of psbA genes were expressed from each cyanobacterium, and the dominant psbA transcripts were from an atypical microaerobic type of D1 protein from Phormidium. Further, cyanobacterial transcripts for photosystem I genes were more abundant than those for photosystem II, and two types of Phormidium sulfide quinone reductase were recovered, consistent with anoxygenic photosynthesis via photosystem I in the presence of sulfide. Transcripts indicate active sulfur oxidation and reduction within the cyanobacterial mat, predominately by Gammaproteobacteria and Deltaproteobacteria, respectively. Overall, these genomic and transcriptomic results link specific microbial groups to metabolic processes that underpin primary production and biogeochemical cycling in a low-O2 cyanobacterial mat and suggest mechanisms for tightly coupled cycling of oxygen and sulfur compounds in the mat ecosystem. IMPORTANCE Cyanobacterial mats are dense communities of microorganisms that contain photosynthetic cyanobacteria along with a host of other bacterial species that play important yet still poorly understood roles in this ecosystem. Although such cyanobacterial mats were critical agents of Earth’s biological and chemical evolution through geological time, little is known about how they function under the low-oxygen conditions that characterized most of their natural history. Here, we performed sequencing of the DNA and RNA of modern cyanobacterial mat communities under low-oxygen and sulfur-rich conditions from the Middle Island sinkhole in Lake Huron. The results reveal the organisms and metabolic pathways that are responsible for both oxygen-producing and non-oxygen-producing photosynthesis as well as interconversions of sulfur that likely shape how much O2 is produced in such ecosystems. These findings indicate tight metabolic reactions between community members that help to explain the limited the amount of O2 produced in cyanobacterial mat ecosystems.
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Sarasa-Buisan C, Guio J, Broset E, Peleato ML, Fillat MF, Sevilla E. FurC (PerR) from Anabaena sp. PCC7120: a versatile transcriptional regulator engaged in the regulatory network of heterocyst development and nitrogen fixation. Environ Microbiol 2021; 24:566-582. [PMID: 33938105 DOI: 10.1111/1462-2920.15552] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/19/2021] [Accepted: 04/30/2021] [Indexed: 11/29/2022]
Abstract
FurC (PerR) from Anabaena sp. PCC7120 was previously described as a key transcriptional regulator involved in setting off the oxidative stress response. In the last years, the cross-talk between oxidative stress, iron homeostasis and nitrogen metabolism is becoming more and more evident. In this work, the transcriptome of a furC-overexpressing strain was compared with that of a wild-type strain under both standard and nitrogen-deficiency conditions. The results showed that the overexpression of furC deregulates genes involved in several categories standing out photosynthesis, iron transport and nitrogen metabolism. The novel FurC-direct targets included some regulatory elements that control heterocyst development (hetZ and asr1734), genes directly involved in the heterocyst envelope formation (devBCA and hepC) and genes which participate in the nitrogen fixation process (nifHDK and nifH2, rbrA rubrerythrin and xisHI excisionase). Likewise, furC overexpression notably impacts the mRNA levels of patA encoding a key protein in the heterocyst pattern formation. The relevance of FurC in these processes is bringing out by the fact that the overexpression of furC impairs heterocyst development and cell growth under nitrogen step-down conditions. In summary, this work reveals a new player in the complex regulatory network of heterocyst formation and nitrogen fixation.
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Affiliation(s)
- Cristina Sarasa-Buisan
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - Jorge Guio
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - Esther Broset
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - M Luisa Peleato
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - María F Fillat
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - Emma Sevilla
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
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16
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Lumian JE, Jungblut AD, Dillion ML, Hawes I, Doran PT, Mackey TJ, Dick GJ, Grettenberger CL, Sumner DY. Metabolic Capacity of the Antarctic Cyanobacterium Phormidium pseudopriestleyi That Sustains Oxygenic Photosynthesis in the Presence of Hydrogen Sulfide. Genes (Basel) 2021; 12:genes12030426. [PMID: 33809699 PMCID: PMC8002359 DOI: 10.3390/genes12030426] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/05/2021] [Accepted: 03/12/2021] [Indexed: 01/11/2023] Open
Abstract
Sulfide inhibits oxygenic photosynthesis by blocking electron transfer between H2O and the oxygen-evolving complex in the D1 protein of Photosystem II. The ability of cyanobacteria to counter this effect has implications for understanding the productivity of benthic microbial mats in sulfidic environments throughout Earth history. In Lake Fryxell, Antarctica, the benthic, filamentous cyanobacterium Phormidium pseudopriestleyi creates a 1–2 mm thick layer of 50 µmol L−1 O2 in otherwise sulfidic water, demonstrating that it sustains oxygenic photosynthesis in the presence of sulfide. A metagenome-assembled genome of P. pseudopriestleyi indicates a genetic capacity for oxygenic photosynthesis, including multiple copies of psbA (encoding the D1 protein of Photosystem II), and anoxygenic photosynthesis with a copy of sqr (encoding the sulfide quinone reductase protein that oxidizes sulfide). The genomic content of P. pseudopriestleyi is consistent with sulfide tolerance mechanisms including increasing psbA expression or directly oxidizing sulfide with sulfide quinone reductase. However, the ability of the organism to reduce Photosystem I via sulfide quinone reductase while Photosystem II is sulfide-inhibited, thereby performing anoxygenic photosynthesis in the presence of sulfide, has yet to be demonstrated.
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Affiliation(s)
- Jessica E. Lumian
- Microbiology Graduate Group, University of California, Davis, CA 95616, USA;
| | - Anne D. Jungblut
- Life Sciences Department, The Natural History Museum, London SW7 5BD, UK;
| | - Megan L. Dillion
- Genomics and Bioinformatics, Novozymes, Inc., Davis, CA 95616, USA;
| | - Ian Hawes
- Coastal Marine Field Station, University of Waikato, Tauranga 3110, New Zealand;
| | - Peter T. Doran
- Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA;
| | - Tyler J. Mackey
- Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, USA;
| | - Gregory J. Dick
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109, USA;
| | | | - Dawn Y. Sumner
- Department of Earth and Planetary Sciences, University of California, Davis, CA 95616, USA;
- Correspondence: ; Tel.: +1-530-752-5353
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Jin H, Lao YM, Ying KZ, Zhou J, Cai ZH. Stringent Response Regulates Stress Resistance in Cyanobacterium Microcystis aeruginosa. Front Microbiol 2020; 11:511801. [PMID: 33281752 PMCID: PMC7688982 DOI: 10.3389/fmicb.2020.511801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 10/16/2020] [Indexed: 11/20/2022] Open
Abstract
Cyanobacterial blooms are serious environmental issues in global freshwater ecosystems. Nitrogen limitation is one of the most important strategies to control cyanobacterial blooms. However, recent researches showed that N limitation does not effectively control the bloom; oppositely, N limitation induces N-fixing cyanobacterial blooms. The mechanism underlying this ecological event is elusive. In this study, we found that N limitation enhances stress tolerance of Microcystis aeruginosa by triggering stringent response (SR), one of the most important bacterial adaptive responses to environmental stresses. Initiation of SR exerted protective effects on the cells against salt and oxidative stresses by promoting colony formation, maintaining membrane integrity, increasing photosynthetic performance, reducing ROS production, upregulating stress-related genes, etc. These protections possibly help M. aeruginosa maintain their population number during seasonal N limitation. As SR has been proven to be involved in nitrogen fixing under N limitation conditions, the potential role of SR in driving the shift and succession of cyanobacterial blooms was discussed. Our findings provide cellular evidence and possible mechanisms that reducing N input is ineffective for bloom control.
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Affiliation(s)
- Hui Jin
- Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, China
| | - Yong Min Lao
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Ke Zhen Ying
- Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
| | - Jin Zhou
- Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
| | - Zhong Hua Cai
- Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
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18
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Mao F, He Y, Gin KYH. Antioxidant responses in cyanobacterium Microcystis aeruginosa caused by two commonly used UV filters, benzophenone-1 and benzophenone-3, at environmentally relevant concentrations. JOURNAL OF HAZARDOUS MATERIALS 2020; 396:122587. [PMID: 32335379 DOI: 10.1016/j.jhazmat.2020.122587] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Benzophenone-type ultraviolet filters (BPs) have recently been recognized as emerging organic contaminants. In the present study, the cyanobacterium Microcystis aeruginosa was exposed to environmentally relevant levels (0.01-1000 μg L-1) of benzophenone-1 (BP-1) and benzophenone-3 (BP-3) for seven days. A battery of tested endpoints associated with photosynthetic pigments and oxidative stress was employed for a better understanding of the mode of action. The tested cyanobacterium could uptake the two BPs (27.4-54.9%) from culture media. The two BPs were able to inhibit the production of chlorophyll a (chl-a) and promote the accumulation of carotenoids, leading to unaffected chl-a autofluorescence. Slightly increased malondialdehyde (MDA) contents suggested that BP-1 and BP-3 caused moderate oxidative stress. BP-1 stimulated the activities of superoxide dismutase (SOD), glutathione reductase (GR) and glutathione S-transferase (GST) in M. aeruginosa while BP-3 increased the activities of SOD, GST, and glutathione (GSH), showing a concentration- and time-dependent relationship. The activities of other biomarkers, such as catalase (CAT) and glutathione peroxidase (GPx) fluctuated depending on exposure time and concentration. The overall results suggested that the two BPs can trigger moderate oxidative stress in M. aeruginosa and the tested cyanobacterium was capable of alleviating stress by different mechanisms.
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Affiliation(s)
- Feijian Mao
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore 117411, Singapore
| | - Yiliang He
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Karina Yew-Hoong Gin
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore 117411, Singapore; Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, E1A 07-03, Singapore 117576, Singapore.
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19
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The Role of Chloroplast Gene Expression in Plant Responses to Environmental Stress. Int J Mol Sci 2020; 21:ijms21176082. [PMID: 32846932 PMCID: PMC7503970 DOI: 10.3390/ijms21176082] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/16/2022] Open
Abstract
Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent. Here, we discuss the emerging roles of the distinct chloroplast gene expression processes in plant responses to environmental stresses. For example, the transcription and translation of psbA play an important role in high-light stress responses. A better understanding of the connection between chloroplast gene expression and environmental stress responses is crucial for breeding stress-tolerant crops better able to cope with the rapidly changing environment.
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20
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Sheridan KJ, Duncan EJ, Eaton-Rye JJ, Summerfield TC. The diversity and distribution of D1 proteins in cyanobacteria. PHOTOSYNTHESIS RESEARCH 2020; 145:111-128. [PMID: 32556852 DOI: 10.1007/s11120-020-00762-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 05/25/2020] [Indexed: 06/11/2023]
Abstract
The psbA gene family in cyanobacteria encodes different forms of the D1 protein that is part of the Photosystem II reaction centre. We have identified a phylogenetically distinct D1 group that is intermediate between previously identified G3-D1 and G4-D1 proteins (Cardona et al. Mol Biol Evol 32:1310-1328, 2015). This new group contained two subgroups: D1INT, which was frequently in the genomes of heterocystous cyanobacteria and D1FR that was part of the far-red light photoacclimation gene cluster of cyanobacteria. In addition, we have identified subgroups within G3, the micro-aerobically expressed D1 protein. There are amino acid changes associated with each of the subgroups that might affect the function of Photosystem II. We show a phylogenetically broad range of cyanobacteria have these D1 types, as well as the genes encoding the G2 protein and chlorophyll f synthase. We suggest identification of additional D1 isoforms and the presence of multiple D1 isoforms in phylogenetically diverse cyanobacteria supports the role of these proteins in conferring a selective advantage under specific conditions.
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Affiliation(s)
- Kevin J Sheridan
- Department of Botany, University of Otago, Dunedin, New Zealand
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Elizabeth J Duncan
- Department of Biological Sciences, School of Biology, University of Leeds, Leeds, UK
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21
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Müh F, Zouni A. Structural basis of light-harvesting in the photosystem II core complex. Protein Sci 2020; 29:1090-1119. [PMID: 32067287 PMCID: PMC7184784 DOI: 10.1002/pro.3841] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 02/06/2020] [Accepted: 02/06/2020] [Indexed: 12/20/2022]
Abstract
Photosystem II (PSII) is a membrane-spanning, multi-subunit pigment-protein complex responsible for the oxidation of water and the reduction of plastoquinone in oxygenic photosynthesis. In the present review, the recent explosive increase in available structural information about the PSII core complex based on X-ray crystallography and cryo-electron microscopy is described at a level of detail that is suitable for a future structure-based analysis of light-harvesting processes. This description includes a proposal for a consistent numbering scheme of protein-bound pigment cofactors across species. The structural survey is complemented by an overview of the state of affairs in structure-based modeling of excitation energy transfer in the PSII core complex with emphasis on electrostatic computations, optical properties of the reaction center, the assignment of long-wavelength chlorophylls, and energy trapping mechanisms.
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Affiliation(s)
- Frank Müh
- Department of Theoretical Biophysics, Institute for Theoretical Physics, Johannes Kepler University Linz, Linz, Austria
| | - Athina Zouni
- Humboldt-Universität zu Berlin, Institute for Biology, Biophysics of Photosynthesis, Berlin, Germany
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22
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Pohland AC, Schneider D. Mg2+ homeostasis and transport in cyanobacteria - at the crossroads of bacterial and chloroplast Mg2+ import. Biol Chem 2020; 400:1289-1301. [PMID: 30913030 DOI: 10.1515/hsz-2018-0476] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/19/2019] [Indexed: 12/29/2022]
Abstract
Magnesium cation (Mg2+) is the most abundant divalent cation in living cells, where it is required for various intracellular functions. In chloroplasts and cyanobacteria, established photosynthetic model systems, Mg2+ is the central ion in chlorophylls, and Mg2+ flux across the thylakoid membrane is required for counterbalancing the light-induced generation of a ΔpH across the thylakoid membrane. Yet, not much is known about Mg2+ homoeostasis, transport and distribution within cyanobacteria. However, Mg2+ transport across membranes has been studied in non-photosynthetic bacteria, and first observations and findings are reported for chloroplasts. Cyanobacterial cytoplasmic membranes appear to contain the well-characterized Mg2+ channels CorA and/or MgtE, which both facilitate transmembrane Mg2+ flux down the electrochemical gradient. Both Mg2+ channels are typical for non-photosynthetic bacteria. Furthermore, Mg2+ transporters of the MgtA/B family are also present in the cytoplasmic membrane to mediate active Mg2+ import into the bacterial cell. While the cytoplasmic membrane of cyanobacteria resembles a 'classical' bacterial membrane, essentially nothing is known about Mg2+ channels and/or transporters in thylakoid membranes of cyanobacteria or chloroplasts. As discussed here, at least one Mg2+ channelling protein must be localized within thylakoid membranes. Thus, either one of the 'typical' bacterial Mg2+ channels has a dual localization in the cytoplasmic plus the thylakoid membrane, or another, yet unidentified channel is present in cyanobacterial thylakoid membranes.
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Affiliation(s)
- Anne-Christin Pohland
- Institut für Pharmazie und Biochemie, Johannes-Gutenberg-Universität Mainz, Johann-Joachim-Becher-Weg 30, D-55128 Mainz, Germany
| | - Dirk Schneider
- Institut für Pharmazie und Biochemie, Johannes-Gutenberg-Universität Mainz, Johann-Joachim-Becher-Weg 30, D-55128 Mainz, Germany
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23
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Aikawa S, Nishida A, Hasunuma T, Chang JS, Kondo A. Short-Term Temporal Metabolic Behavior in Halophilic Cyanobacterium Synechococcus sp. Strain PCC 7002 after Salt Shock. Metabolites 2019; 9:metabo9120297. [PMID: 31817542 PMCID: PMC6950573 DOI: 10.3390/metabo9120297] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 11/16/2022] Open
Abstract
In response to salt stress, cyanobacteria increases the gene expression of Na+/H+ antiporter and K+ uptake system proteins and subsequently accumulate compatible solutes. However, alterations in the concentrations of metabolic intermediates functionally related to the early stage of the salt stress response have not been investigated. The halophilic cyanobacterium Synechococcus sp. PCC 7002 was subjected to salt shock with 0.5 and 1 M NaCl, then we performed metabolomics analysis by capillary electrophoresis/mass spectrometry (CE/MS) and gas chromatography/mass spectrometry (GC/MS) after cultivation for 1, 3, 10, and 24 h. Gene expression profiling using a microarray after 1 h of salt shock was also conducted. We observed suppression of the Calvin cycle and activation of glycolysis at both NaCl concentrations. However, there were several differences in the metabolic changes after salt shock following exposure to 0.5 M and 1 M NaCl: (i): the main compatible solute, glucosylglycerol, accumulated quickly at 0.5 M NaCl after 1 h but increased gradually for 10 h at 1 M NaCl; (ii) the oxidative pentose phosphate pathway and the tricarboxylic acid cycle were activated at 0.5 M NaCl; and (iii) the multi-functional compound spermidine greatly accumulated at 1 M NaCl. Our results show that Synechococcus sp. PCC 7002 acclimated to different levels of salt through a salt stress response involving the activation of different metabolic pathways.
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Affiliation(s)
- Shimpei Aikawa
- Graduate School of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan; (S.A.); (A.K.)
| | - Atsumi Nishida
- Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan;
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan; (S.A.); (A.K.)
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
- Correspondence: ; Tel.: +81-78-803-6356
| | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan;
- Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan
- Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Akihiko Kondo
- Graduate School of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan; (S.A.); (A.K.)
- Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan;
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe 657-8501, Japan
- Biomass Engineering Program, RIKEN, 1-7-22 Suehiro, Tsurumi-ku, Yokohama 230-0045, Japan
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Bhoite R, Si P, Liu H, Xu L, Siddique KHM, Yan G. Inheritance of pre-emergent metribuzin tolerance and putative gene discovery through high-throughput SNP array in wheat (Triticum aestivum L.). BMC PLANT BIOLOGY 2019; 19:457. [PMID: 31664905 PMCID: PMC6821039 DOI: 10.1186/s12870-019-2070-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 10/09/2019] [Indexed: 05/28/2023]
Abstract
BACKGROUND Herbicide tolerance is an important trait that allows effective weed management in wheat crops in dryland farming. Genetic knowledge of metribuzin tolerance in wheat is needed to develop new cultivars for the industry. Here, we investigated gene effects for metribuzin tolerance in nine crosses of wheat by partitioning the means and variances of six basic generations from each cross into their genetic components to assess the gene action governing the inheritance of this trait. Metribuzin tolerance was measured by a visual senescence score 21 days after treatment. The wheat 90 K iSelect SNP genotyping assay was used to identify the distribution of alleles at SNP sites in tolerant and susceptible groups. RESULTS The scaling and joint-scaling tests indicated that the inheritance of metribuzin tolerance in wheat was adequately described by the additive-dominance model, with additive gene action the most significant factor for tolerance. The potence ratio for all the crosses ranged between - 1 and + 1 for senescence under metribuzin-treated conditions indicating a semi-dominant gene action in the inheritance of metribuzin tolerance in wheat. The number of segregating genes governing metribuzin tolerance was estimated between 3 and 15. The consistent high heritability range (0.82 to 0.92) in F5-7 generations of Chuan Mai 25 (tolerant) × Ritchie (susceptible) cross indicated a significant contribution of additive genetic effects to metribuzin tolerance in wheat. Several genes related to photosynthesis (e.g. photosynthesis system II assembly factor YCF48), metabolic detoxification of xenobiotics and cell growth and development (cytochrome P450, glutathione S-transferase, glycosyltransferase, ATP-binding cassette transporters and glutathione peroxidase) were identified on different chromosomes (2A, 2D, 3B, 4A, 4B, 7A, 7B, 7D) governing metribuzin tolerance. CONCLUSIONS The simple additive-dominance gene effects for metribuzin tolerance will help breeders to select tolerant lines in early generations and the identified genes may guide the development of functional markers for metribuzin tolerance.
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Affiliation(s)
- Roopali Bhoite
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009 Australia
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6009 Australia
| | - Ping Si
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009 Australia
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6009 Australia
| | - Hui Liu
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009 Australia
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6009 Australia
| | - Ling Xu
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009 Australia
- Zhejiang Province Key Laboratory of Plant Secondary Metabolism and Regulation, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, 310018 People’s Republic of China
| | - Kadambot H. M. Siddique
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6009 Australia
| | - Guijun Yan
- UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009 Australia
- The UWA Institute of Agriculture, The University of Western Australia, Perth, WA 6009 Australia
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25
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Carbonell V, Vuorio E, Aro EM, Kallio P. Enhanced stable production of ethylene in photosynthetic cyanobacterium Synechococcus elongatus PCC 7942. World J Microbiol Biotechnol 2019; 35:77. [PMID: 31069553 PMCID: PMC6536634 DOI: 10.1007/s11274-019-2652-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 04/26/2019] [Indexed: 11/26/2022]
Abstract
Ethylene is a volatile alkene which is used in large commercial scale as a precursor in plastic industry, and is currently derived from petroleum refinement. As an alternative production strategy, photoautotrophic cyanobacteria Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942 have been previously evaluated as potential biotechnological hosts for producing ethylene directly from CO2, by the over-expression of ethylene forming enzyme (efe) from Pseudomonas syringae. This work addresses various open questions related to the use of Synechococcus as the engineering target, and demonstrates long-term ethylene production at rates reaching 140 µL L−1 h−1 OD750−1 without loss of host vitality or capacity to produce ethylene. The results imply that the genetic instability observed earlier may be associated with the expression strategies, rather than efe over-expression, ethylene toxicity or the depletion of 2-oxoglutarate—derived cellular precursors in Synechococcus. In context with literature, this study underlines the critical differences in expression system design in the alternative hosts, and confirms Synechococcus as a suitable parallel host for further engineering.
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Affiliation(s)
- Veronica Carbonell
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turun yliopisto, Finland
| | - Eerika Vuorio
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turun yliopisto, Finland
| | - Eva-Mari Aro
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turun yliopisto, Finland
| | - Pauli Kallio
- Molecular Plant Biology, Department of Biochemistry, University of Turku, 20014, Turun yliopisto, Finland.
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Oren N, Raanan H, Kedem I, Turjeman A, Bronstein M, Kaplan A, Murik O. Desert cyanobacteria prepare in advance for dehydration and rewetting: The role of light and temperature sensing. Mol Ecol 2019; 28:2305-2320. [DOI: 10.1111/mec.15074] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/05/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Nadav Oren
- Department of Plant and Environmental Sciences The Hebrew University of Jerusalem Jerusalem Israel
| | - Hagai Raanan
- Department of Plant and Environmental Sciences The Hebrew University of Jerusalem Jerusalem Israel
- Environmental Biophysics and Molecular Ecology Program, Institute of Earth, Ocean and Atmospheric Sciences Rutgers University New Brunswick New Jersey
| | - Isaac Kedem
- Department of Plant and Environmental Sciences The Hebrew University of Jerusalem Jerusalem Israel
| | - Adi Turjeman
- The Center for Genomic Technologies The Hebrew University of Jerusalem Jerusalem Israel
| | - Michal Bronstein
- The Center for Genomic Technologies The Hebrew University of Jerusalem Jerusalem Israel
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences The Hebrew University of Jerusalem Jerusalem Israel
| | - Omer Murik
- Department of Plant and Environmental Sciences The Hebrew University of Jerusalem Jerusalem Israel
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27
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Xu HF, Dai GZ, Qiu BS. Weak red light plays an important role in awakening the photosynthetic machinery following desiccation in the subaerial cyanobacterium Nostoc flagelliforme. Environ Microbiol 2019; 21:2261-2272. [PMID: 30895692 DOI: 10.1111/1462-2920.14600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/31/2019] [Accepted: 03/19/2019] [Indexed: 11/28/2022]
Abstract
The subaerial cyanobacterium Nostoc flagelliforme can survive for years in the desiccated state and light exposure may stimulate photosynthetic recovery during rehydration. However, the influence of light quality on photosynthetic recovery and the underlying mechanism remain unresolved. Exposure of field collected N. flagelliforme to light intensity ≥2 μmol photons m-2 s-1 showed that the speed of photosystem II (PSII) recovery was in the following order: red > green > blue ≈ violet light. Decreasing the light intensity showed that weak red light stimulated PSII recovery during rehydration. The chlorophyll fluorescence transient and oxygen evolution activity indicated that the oxygen evolution complex (OEC) was the activated site triggered by weak red light. The damaged D1 protein accumulated in the thylakoid membrane during dehydration and is degraded and resynthesized during dark rehydration. PsbO interaction with the thylakoid membrane was induced by weak red light. Thus, weak red light plays an important role in triggering OEC photoactivation and the formation of functional PSII during rehydration. In its arid habitats, weak red light could stimulate the awakening of dormant N. flagelliforme after absorbing water from nighttime dew or rain to maximize growth during the early daylight hours of the dry season.
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Affiliation(s)
- Hai-Feng Xu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, Hubei, 430079, P. R. China
| | - Guo-Zheng Dai
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, Hubei, 430079, P. R. China
| | - Bao-Sheng Qiu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, Hubei, 430079, P. R. China
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28
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Sicora CI, Chiș I, Chiș C, Sicora O. Regulation of PSII function in Cyanothece sp. ATCC 51142 during a light-dark cycle. PHOTOSYNTHESIS RESEARCH 2019; 139:461-473. [PMID: 30357676 DOI: 10.1007/s11120-018-0598-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 10/15/2018] [Indexed: 06/08/2023]
Abstract
Cyanobacteria, as well as green algae and higher plants, have highly conserved photosynthetic machinery. Cyanothece sp. ATCC 51142 is a unicellular, aerobic, diazotrophic cyanobacterium that fixes N2 in the dark. In Cyanothece, the psbA gene family is composed of five members, encoding different isoforms of the D1 protein. A new D1 protein has been postulated in the literature, which blocks PSII during the night and allows the fixation of nitrogen. We present data showing changes in PSII function in cells grown in cycles alternating between 12 h of light and dark, respectively, at Cyanothece sp. ATCC 51142. Cyanothece sp. ATCC 51142 uses intrinsic mechanisms to protect its nitrogenase activity in a two-stage process. In Stage I, immediately after the onset of darkness, the cells lose photosynthetic activity in a reversible process, probably by dissociation of water oxidation complex from photosystem II via a mechanism that does not require de novo protein synthesis. In Stage II, a more severe disruption of photosystem II function occurs is in part protein synthesis dependent and it could be a functional signature of the presence of sentinel D1 in a limited number of reaction centers still active or not yet inactivated by the mechanism described in Stage I. This process of inhibition uses light as a triggering signal for both the inhibition of photosynthetic activity and recovery when light returns. The intrinsic mechanism of photosynthetic inactivation during darkness with the interplay of the two mechanisms requires further studies.
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Affiliation(s)
- Cosmin Ionel Sicora
- Biological Research Center Jibou, 16 Wesselenyi Street, 455200, Jibou, Sălaj, Romania.
| | - Iuliana Chiș
- Biological Research Center Jibou, 16 Wesselenyi Street, 455200, Jibou, Sălaj, Romania
| | - Ciprian Chiș
- Biological Research Center Jibou, 16 Wesselenyi Street, 455200, Jibou, Sălaj, Romania
| | - Oana Sicora
- Biological Research Center Jibou, 16 Wesselenyi Street, 455200, Jibou, Sălaj, Romania
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29
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Marchello AE, Oliveira NL, Lombardi AT, Polpo A. An investigation onto Cd toxicity to freshwater microalga Chlorella sorokiniana in mixotrophy and photoautotrophy: A Bayesian approach. CHEMOSPHERE 2018; 211:794-803. [PMID: 30099164 DOI: 10.1016/j.chemosphere.2018.08.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 08/04/2018] [Accepted: 08/06/2018] [Indexed: 05/28/2023]
Abstract
Aquatic ecosystems are composed by a myriad of dissolved organic materials that can be assimilated by microalgae, while they can perform photosynthesis, this is refereed as mixotrophy. However, ecotoxicological tests usually consider only the photoautotrophic metabolism. This research investigated the ecotoxicological differences between photoautotrophy and mixotrophy in Chlorella sorokiniana exposed to cadmium (Cd). Chlorophyll a, photosynthetic efficiency (Fv/Fm), cell viability, biochemical composition and pH were used to monitor possible toxic effects at 72 h cultures. Glucose (1 g.L-1) was used as organic carbon source. To evaluate the probability of the photoautotrophic culture being more affected by Cd than the mixotrophic one, Bayesian statistical analysis was performed. The photoautotrophic cultures were more affected by Cd than the mixotrophic ones, with reduction of all evaluated parameters, except for protein concentration. However, in mixotrophic cultures, no changes in protein concentration and proteins:carbohydrates ratio were observed, and chlorophyll a, Fv/Fm and cell viability were only affected at the high Cd concentrations (range ln -11.5 to -9.4). However, both mixotrophy and photoautotrophy had the same probability of having the carbohydrates concentration affected by Cd. We conclude that the microalgae in mixotrophy were more resistant to the Cd than in photoautotrophy. In addition, we showed that under photoautotrophy Fv/Fm decreased linearly as Cd concentration increased, but in mixotrophy no effect was observed up to 10-5 molL-1 Cd, after which it decreased. We rationale that the reduced photosynthetic capacity under mixotrophy can end up reducing the release of oxygen gas, which can compromise the entire aquatic ecosystem.
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Affiliation(s)
- Adriano Evandir Marchello
- Laboratory of Algal Biotechnology, Department of Botany, Federal University of São Carlos, São Carlos, Brazil; Post-graduate in Ecology and Natural Resources, Center of Biological and Health Sciences, Federal University of São Carlos, São Carlos, Brazil.
| | | | - Ana Teresa Lombardi
- Laboratory of Algal Biotechnology, Department of Botany, Federal University of São Carlos, São Carlos, Brazil
| | - Adriano Polpo
- Department of Statistics, Center of Exact Sciences and Technology, Federal University of São Carlos, São Carlos, Brazil
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Ahlgren NA, Fuchsman CA, Rocap G, Fuhrman JA. Discovery of several novel, widespread, and ecologically distinct marine Thaumarchaeota viruses that encode amoC nitrification genes. ISME JOURNAL 2018; 13:618-631. [PMID: 30315316 DOI: 10.1038/s41396-018-0289-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 06/15/2018] [Accepted: 09/19/2018] [Indexed: 12/22/2022]
Abstract
Much of the diversity of prokaryotic viruses has yet to be described. In particular, there are no viral isolates that infect abundant, globally significant marine archaea including the phylum Thaumarchaeota. This phylum oxidizes ammonia, fixes inorganic carbon, and thus contributes to globally significant nitrogen and carbon cycles in the oceans. Metagenomics provides an alternative to culture-dependent means for identifying and characterizing viral diversity. Some viruses carry auxiliary metabolic genes (AMGs) that are acquired via horizontal gene transfer from their host(s), allowing inference of what host a virus infects. Here we present the discovery of 15 new genomically and ecologically distinct Thaumarchaeota virus populations, identified as contigs that encode viral capsid and thaumarchaeal ammonia monooxygenase genes (amoC). These viruses exhibit depth and latitude partitioning and are distributed globally in various marine habitats including pelagic waters, estuarine habitats, and hydrothermal plume water and sediments. We found evidence of viral amoC expression and that viral amoC AMGs sometimes comprise up to half of total amoC DNA copies in cellular fraction metagenomes, highlighting the potential impact of these viruses on N cycling in the oceans. Phylogenetics suggest they are potentially tailed viruses and share a common ancestor with related marine Euryarchaeota viruses. This work significantly expands our view of viruses of globally important marine Thaumarchaeota.
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Affiliation(s)
- Nathan A Ahlgren
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA. .,Clark University, Worcester, MA, USA.
| | - Clara A Fuchsman
- School of Oceanography, University of Washington, Seattle, WA, USA.,Horn Point Laboratory, University of Maryland, Cambridge, MD, USA
| | - Gabrielle Rocap
- School of Oceanography, University of Washington, Seattle, WA, USA
| | - Jed A Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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31
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Arisaka S, Sukigara H, Osanai T. Genetic manipulation to overexpress rpaA altered photosynthetic electron transport in Synechocystis sp. PCC 6803. J Biosci Bioeng 2018. [DOI: 10.1016/j.jbiosc.2018.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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32
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Ooka H, Hashimoto K, Nakamura R. Design Strategy of Multi-electron Transfer Catalysts Based on a Bioinformatic Analysis of Oxygen Evolution and Reduction Enzymes. Mol Inform 2018; 37:e1700139. [PMID: 29756682 PMCID: PMC6282526 DOI: 10.1002/minf.201700139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/05/2018] [Indexed: 12/01/2022]
Abstract
Understanding the design strategy of photosynthetic and respiratory enzymes is important to develop efficient artificial catalysts for oxygen evolution and reduction reactions. Here, based on a bioinformatic analysis of cyanobacterial oxygen evolution and reduction enzymes (photosystem II: PS II and cytochrome c oxidase: COX, respectively), the gene encoding the catalytic D1 subunit of PS II was found to be expressed individually across 38 phylogenetically diverse strains, which is in contrast to the operon structure of the genes encoding major COX subunits. Selective synthesis of the D1 subunit minimizes the repair cost of PS II, which allows compensation for its instability by lowering the turnover number required to generate a net positive energy yield. The different bioenergetics observed between PS II and COX suggest that in addition to the catalytic activity rationalized by the Sabatier principle, stability factors have also provided a major influence on the design strategy of biological multi-electron transfer enzymes.
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Affiliation(s)
- Hideshi Ooka
- Department of Applied ChemistryThe University of Tokyo7-3-1 HongoBunkyo-ku, Tokyo113-8656Japan
- Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science (CSRS)2-1 HirosawaWako, Saitama351-0198Japan
| | - Kazuhito Hashimoto
- National Institute for Materials Science (NIMS)1-2-1 SengenTsukuba, Ibaraki305-0047Japan
| | - Ryuhei Nakamura
- Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science (CSRS)2-1 HirosawaWako, Saitama351-0198Japan
- Earth-Life Science Institute (ELSI)Tokyo Institute of Technology2-12-1-IE-1 OokayamaMeguro-ku, Tokyo152-8550Japan
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Li S, Sun T, Xu C, Chen L, Zhang W. Development and optimization of genetic toolboxes for a fast-growing cyanobacterium Synechococcus elongatus UTEX 2973. Metab Eng 2018; 48:163-174. [PMID: 29883802 DOI: 10.1016/j.ymben.2018.06.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/02/2018] [Accepted: 06/04/2018] [Indexed: 10/14/2022]
Abstract
The fast-growing cyanobacterium Synechococcus elongatus UTEX 2973 (hereafter Synechococcus 2973) has been considered a good chassis candidate for "microbial cell factory" as it can perform oxygenic photosynthesis and its doubling time can be as short as 1.9 h. However, the limited genetic tools currently restrict its further research and application efforts using synthetic biology approaches. In this study, a series of genetic tools were systematically developed and optimized for Synechococcus 2973. First, the introduction of Tfp pilus assembly protein encoding gene pilN into Synechococcus 2973 successfully recovered its natural transformability, which greatly simplified the DNA transformation process. Second, a series of promoters with different strengths were evaluated and the super-strong promoters including Pcpc560 from Synechocystis sp. PCC 6803, native PpsbA2 and PpsbA3 of Synechococcus 2973 were found with the highest activity of β-galactosidase among those evaluated by miller values. Some promoters related to photosystems (i.e., PpsbA2, PpsbA3, P6803psbA2 and Pcpc560) were also demonstrated to be induced by high intensity of light. Third, three lactose induction systems were evaluated, among which Plac combined with lacIq showed the best application prospect with great induction capacity, low leakage and middle induced expression. Fourth, the translational on riboswitch theoE* , the transcriptional off riboswitches theo/yitJ and xpt(C74U)/metE and an artificial inducing system combining theoE* with T7 RNA polymerase were successfully developed and characterized in Synechococcus 2973. Finally, by using T7 induction system to control the expression of both small RNA and chaperone Hfq, a small RNA regulatory tool was developed and optimized to be a strictly inducible off system for gene regulation in Synechococcus 2973. The work here presented valuable genetic toolboxes necessary for metabolic engineering and synthetic biology research in Synechococcus 2973, which will facilitate the future application of the fast growing cyanobacterial chassis.
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Affiliation(s)
- Shubin Li
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Tao Sun
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Chunxiao Xu
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China.
| | - Weiwen Zhang
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, PR China; Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, PR China; Center for Biosafety Research and Strategy, Tianjin University, Tianjin, PR China
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Cardona T, Shao S, Nixon PJ. Enhancing photosynthesis in plants: the light reactions. Essays Biochem 2018; 62:85-94. [PMID: 29563222 PMCID: PMC5897789 DOI: 10.1042/ebc20170015] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 01/23/2018] [Accepted: 01/29/2018] [Indexed: 12/20/2022]
Abstract
In this review, we highlight recent research and current ideas on how to improve the efficiency of the light reactions of photosynthesis in crops. We note that the efficiency of photosynthesis is a balance between how much energy is used for growth and the energy wasted or spent protecting the photosynthetic machinery from photodamage. There are reasons to be optimistic about enhancing photosynthetic efficiency, but many appealing ideas are still on the drawing board. It is envisioned that the crops of the future will be extensively genetically modified to tailor them to specific natural or artificial environmental conditions.
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Affiliation(s)
- Tanai Cardona
- Department of Life Sciences, Sir Ernst Chain Building - Wolfson Laboratories, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
| | - Shengxi Shao
- Department of Life Sciences, Sir Ernst Chain Building - Wolfson Laboratories, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K
| | - Peter J Nixon
- Department of Life Sciences, Sir Ernst Chain Building - Wolfson Laboratories, Imperial College London, South Kensington Campus, London SW7 2AZ, U.K.
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Zhan J, Wang Q. Photoresponse Mechanism in Cyanobacteria: Key Factor in Photoautotrophic Chassis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1080:75-96. [PMID: 30091092 DOI: 10.1007/978-981-13-0854-3_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
As the oldest oxygenic photoautotrophic prokaryotes, cyanobacteria have outstanding advantages as the chassis cell in the research field of synthetic biology. Cognition of photosynthetic mechanism, including the photoresponse mechanism under high-light (HL) conditions, is important for optimization of the cyanobacteria photoautotrophic chassis for synthesizing biomaterials as "microbial cell factories." Cyanobacteria are well-established model organisms for the study of oxygenic photosynthesis and have evolved various acclimatory responses to HL conditions to protect the photosynthetic apparatus from photodamage. Here, we reviewed the latest progress in the mechanism of HL acclimation in cyanobacteria. The subsequent acclimatory responses and the corresponding molecular mechanisms are included: (1) acclimatory responses of PSII and PSI; (2) the degradation of phycobilisome; (3) induction of the photoprotective mechanisms such as state transitions, OCP-dependent non-photochemical quenching, and the induction of HLIP family; and (4) the regulation mechanisms of the gene expression under HL.
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Affiliation(s)
- Jiao Zhan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Qiang Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan, Hubei, China.
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Motomura T, Suga M, Hienerwadel R, Nakagawa A, Lai TL, Nitschke W, Kuma T, Sugiura M, Boussac A, Shen JR. Crystal structure and redox properties of a novel cyanobacterial heme protein with a His/Cys heme axial ligation and a Per-Arnt-Sim (PAS)-like domain. J Biol Chem 2017; 292:9599-9612. [PMID: 28428249 DOI: 10.1074/jbc.m116.746263] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 04/17/2017] [Indexed: 01/05/2023] Open
Abstract
Photosystem II catalyzes light-induced water oxidation leading to the generation of dioxygen indispensable for sustaining aerobic life on Earth. The Photosystem II reaction center is composed of D1 and D2 proteins encoded by psbA and psbD genes, respectively. In cyanobacteria, different psbA genes are present in the genome. The thermophilic cyanobacterium Thermosynechococcus elongatus contains three psbA genes: psbA1, psbA2, and psbA3, and a new c-type heme protein, Tll0287, was found to be expressed in a strain expressing the psbA2 gene only, but the structure and function of Tll0287 are unknown. Here we solved the crystal structure of Tll0287 at a 2.0 Å resolution. The overall structure of Tll0287 was found to be similar to some kinases and sensor proteins with a Per-Arnt-Sim-like domain rather than to other c-type cytochromes. The fifth and sixth axial ligands for the heme were Cys and His, instead of the His/Met or His/His ligand pairs observed for most of the c-type hemes. The redox potential, E½, of Tll0287 was -255 ± 20 mV versus normal hydrogen electrode at pH values above 7.5. Below this pH value, the E½ increased by ≈57 mV/pH unit at 15 °C, suggesting the involvement of a protonatable group with a pKred = 7.2 ± 0.3. Possible functions of Tll0287 as a redox sensor under microaerobic conditions or a cytochrome subunit of an H2S-oxidizing system are discussed in view of the environmental conditions in which psbA2 is expressed, as well as phylogenetic analysis, structural, and sequence homologies.
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Affiliation(s)
- Taiki Motomura
- From the Department of Picobiology, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan.,the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Michihiro Suga
- the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Rainer Hienerwadel
- the Laboratoire de Génétique et Biophysique des Plantes, UMR 7265, CNRS-CEA-Aix-Marseille Université, Faculté des Sciences de Luminy, 13288 Marseille, France
| | - Akiko Nakagawa
- the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.,the Proteo-Science Research Center, Ehime University, Ehime 790-8577, Japan
| | - Thanh-Lan Lai
- iBiTec-S, SB2SM, CNRS UMR 9198, CEA Saclay, 91191 Gif-sur-Yvette, France, and
| | - Wolfgang Nitschke
- the Laboratoire de Bioénergétique et Ingénierie des Protéines, CNRS UMR 7281, 13402 Marseille Cedex 20, France
| | - Takahiro Kuma
- the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Miwa Sugiura
- the Proteo-Science Research Center, Ehime University, Ehime 790-8577, Japan
| | - Alain Boussac
- iBiTec-S, SB2SM, CNRS UMR 9198, CEA Saclay, 91191 Gif-sur-Yvette, France, and
| | - Jian-Ren Shen
- From the Department of Picobiology, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan, .,the Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
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Smith MJ, Francis MB. A Designed A. vinelandii-S. elongatus Coculture for Chemical Photoproduction from Air, Water, Phosphate, and Trace Metals. ACS Synth Biol 2016; 5:955-61. [PMID: 27232890 DOI: 10.1021/acssynbio.6b00107] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Microbial mutualisms play critical roles in a diverse number of ecosystems and have the potential to improve the efficiency of bioproduction for desirable chemicals. We investigate the growth of a photosynthetic cyanobacterium, Synechococcus elongatus PCC 7942, and a diazotroph, Azotobacter vinelandii, in coculture. From initial studies of the coculture grown in media with glutamate, we proposed a model of cross-feeding between these organisms. We then engineer a new microbial mutualism between Azotobacter vinelandii AV3 and cscB Synechococcus elongatus that grows in the absence of fixed carbon or nitrogen. The coculture cannot grow in the absence of a sucrose-exporting S. elongatus, and neither organism can grow alone without fixed carbon or nitrogen. This new system has the potential to produce industrially relevant products, such as polyhydroxybutyrate (PHB) and alginate, from air, water, phosphate, trace metals, and sunlight. We demonstrate the ability of the coculture to produce PHB in this work.
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Affiliation(s)
- Matthew J. Smith
- Department
of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Matthew B. Francis
- Department
of Chemistry, University of California, Berkeley, California 94720-1460, United States
- The
Molecular Foundry, Materials Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720-1460, United States
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Crawford TS, Hanning KR, Chua JPS, Eaton-Rye JJ, Summerfield TC. Comparison of D1´- and D1-containing PS II reaction centre complexes under different environmental conditions in Synechocystis sp. PCC 6803. PLANT, CELL & ENVIRONMENT 2016; 39:1715-26. [PMID: 26991994 DOI: 10.1111/pce.12738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 02/22/2016] [Accepted: 03/03/2016] [Indexed: 05/24/2023]
Abstract
In oxygenic photosynthesis, the D1 protein of Photosystem II is the primary target of photodamage and environmental stress can accelerate this process. The cyanobacterial response to stress includes transcriptional regulation of genes encoding D1, including low-oxygen-induction of psbA1 encoding the D1´ protein in Synechocystis sp. PCC 6803. The psbA1 gene is also transiently up-regulated in high light, and its deletion has been reported to increase ammonium-induced photoinhibition. Therefore we investigated the role of D1´-containing PS II centres under different environmental conditions. A strain containing only D1´-PS II centres under aerobic conditions exhibited increased sensitivity to ammonium chloride and high light compared to a D1-containing strain. Additionally a D1´-PS II strain was outperformed by a D1-PS II strain under normal conditions; however, a strain containing low-oxygen-induced D1´-PS II centres was more resilient under high light than an equivalent D1 strain. These D1´-containing centres had chlorophyll a fluorescence characteristics indicative of altered forward electron transport and back charge recombination with the donor side of PS II. Our results indicate D1´-PS II centres are important in the reconfiguration of thylakoid electron transport in response to high light and low oxygen.
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Affiliation(s)
- Tim S Crawford
- Department of Botany, University of Otago, Dunedin, 9054, New Zealand
- Department of Biochemistry, University of Otago, Dunedin, 9054, New Zealand
| | - Kyrin R Hanning
- Department of Botany, University of Otago, Dunedin, 9054, New Zealand
| | - Jocelyn P S Chua
- Department of Botany, University of Otago, Dunedin, 9054, New Zealand
| | - Julian J Eaton-Rye
- Department of Biochemistry, University of Otago, Dunedin, 9054, New Zealand
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Gimpel JA, Nour-Eldin HH, Scranton MA, Li D, Mayfield SP. Refactoring the Six-Gene Photosystem II Core in the Chloroplast of the Green Algae Chlamydomonas reinhardtii. ACS Synth Biol 2016. [PMID: 26214707 DOI: 10.1021/acssynbio.5b00076] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Oxygenic photosynthesis provides the energy to produce all food and most of the fuel on this planet. Photosystem II (PSII) is an essential and rate-limiting component of this process. Understanding and modifying PSII function could provide an opportunity for optimizing photosynthetic biomass production, particularly under specific environmental conditions. PSII is a complex multisubunit enzyme with strong interdependence among its components. In this work, we have deleted the six core genes of PSII in the eukaryotic alga Chlamydomonas reinhardtii and refactored them in a single DNA construct. Complementation of the knockout strain with the core PSII synthetic module from three different green algae resulted in reconstitution of photosynthetic activity to 85, 55, and 53% of that of the wild-type, demonstrating that the PSII core can be exchanged between algae species and retain function. The strains, synthetic cassettes, and refactoring strategy developed for this study demonstrate the potential of synthetic biology approaches for tailoring oxygenic photosynthesis and provide a powerful tool for unraveling PSII structure-function relationships.
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Affiliation(s)
- Javier A. Gimpel
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
| | - Hussam H. Nour-Eldin
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
| | - Melissa A. Scranton
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
| | - Daphne Li
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
| | - Stephen P. Mayfield
- California Center for Algae
Biotechnology Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0368, United States
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40
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Weisz DA, Gross ML, Pakrasi HB. The Use of Advanced Mass Spectrometry to Dissect the Life-Cycle of Photosystem II. FRONTIERS IN PLANT SCIENCE 2016; 7:617. [PMID: 27242823 PMCID: PMC4862242 DOI: 10.3389/fpls.2016.00617] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/22/2016] [Indexed: 05/23/2023]
Abstract
Photosystem II (PSII) is a photosynthetic membrane-protein complex that undergoes an intricate, tightly regulated cycle of assembly, damage, and repair. The available crystal structures of cyanobacterial PSII are an essential foundation for understanding PSII function, but nonetheless provide a snapshot only of the active complex. To study aspects of the entire PSII life-cycle, mass spectrometry (MS) has emerged as a powerful tool that can be used in conjunction with biochemical techniques. In this article, we present the MS-based approaches that are used to study PSII composition, dynamics, and structure, and review the information about the PSII life-cycle that has been gained by these methods. This information includes the composition of PSII subcomplexes, discovery of accessory PSII proteins, identification of post-translational modifications and quantification of their changes under various conditions, determination of the binding site of proteins not observed in PSII crystal structures, conformational changes that underlie PSII functions, and identification of water and oxygen channels within PSII. We conclude with an outlook for the opportunity of future MS contributions to PSII research.
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Affiliation(s)
- Daniel A. Weisz
- Department of Biology, Washington University in St. LouisSt. Louis, MO, USA
- Department of Chemistry, Washington University in St. LouisSt. Louis, MO, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. LouisSt. Louis, MO, USA
| | - Himadri B. Pakrasi
- Department of Biology, Washington University in St. LouisSt. Louis, MO, USA
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Vinyard DJ, Sun JS, Gimpel J, Ananyev GM, Mayfield SP, Charles Dismukes G. Natural isoforms of the Photosystem II D1 subunit differ in photoassembly efficiency of the water-oxidizing complex. PHOTOSYNTHESIS RESEARCH 2016; 128:141-150. [PMID: 26687161 DOI: 10.1007/s11120-015-0208-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
Oxygenic photosynthesis efficiency at increasing solar flux is limited by light-induced damage (photoinhibition) of Photosystem II (PSII), primarily targeting the D1 reaction center subunit. Some cyanobacteria contain two natural isoforms of D1 that function better under low light (D1:1) or high light (D1:2). Herein, rates and yields of photoassembly of the Mn4CaO5 water-oxidizing complex (WOC) from the free inorganic cofactors (Mn(2+), Ca(2+), water, electron acceptor) and apo-WOC-PSII are shown to differ significantly: D1:1 apo-WOC-PSII exhibits a 2.3-fold faster rate-limiting step of photoassembly and up to seven-fold faster rate to the first light-stable Mn(3+) intermediate, IM1*, but with a much higher rate of photoinhibition than D1:2. Conversely, D1:2 apo-WOC-PSII assembles slower but has up to seven-fold higher yield, achieved by a higher quantum yield of charge separation and slower photoinhibition rate. These results confirm and extend previous observations of the two holoenzymes: D1:2-PSII has a greater quantum yield of primary charge separation, faster [P680 (+) Q A (-) ] charge recombination and less photoinhibition that results in a slower rate and higher yield of photoassembly of its apo-WOC-PSII complex. In contrast, D1:1-PSII has a lower quantum yield of primary charge separation, a slower [P680 (+) Q A (-) ] charge recombination rate, and faster photoinhibition that together result in higher rate but lower yield of photoassembly at higher light intensities. Cyanobacterial PSII reaction centers that contain the high- and low-light D1 isoforms can tailor performance to optimize photosynthesis at varying light conditions, with similar consequences on their photoassembly kinetics and yield. These different efficiencies of photoassembly versus photoinhibition impose differential costs for biosynthesis as a function of light intensity.
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Affiliation(s)
- David J Vinyard
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Rd., Piscataway, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Jennifer S Sun
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Rd., Piscataway, NJ, 08854, USA
- Department of Molecular, Cellular, and Development Biology, Yale University, New Haven, CT, 06520, USA
| | - Javier Gimpel
- San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
- Centre for Biotechnology and Bioengineering, Universidad de Chile, Santiago, Chile
| | - Gennady M Ananyev
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Rd., Piscataway, NJ, 08854, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Stephen P Mayfield
- San Diego Center for Algae Biotechnology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - G Charles Dismukes
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, 190 Frelinghuysen Rd., Piscataway, NJ, 08854, USA.
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA.
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Kuwahara A, Arisaka S, Takeya M, Iijima H, Hirai MY, Osanai T. Modification of photosynthetic electron transport and amino acid levels by overexpression of a circadian-related histidine kinase hik8 in Synechocystis sp. PCC 6803. Front Microbiol 2015; 6:1150. [PMID: 26539179 PMCID: PMC4611142 DOI: 10.3389/fmicb.2015.01150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/05/2015] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria perform oxygenic photosynthesis, and the maintenance of photosynthetic electron transport chains is indispensable to their survival in various environmental conditions. Photosynthetic electron transport in cyanobacteria can be studied through genetic analysis because of the natural competence of cyanobacteria. We here show that a strain overexpressing hik8, a histidine kinase gene related to the circadian clock, exhibits an altered photosynthetic electron transport chain in the unicellular cyanobacterium Synechocystis sp. PCC 6803. Respiratory activity was down-regulated under nitrogen-replete conditions. Photosynthetic activity was slightly lower in the hik8-overexpressing strain than in the wild-type after nitrogen depletion, and the values of photosynthetic parameters were altered by hik8 overexpression under nitrogen-replete and nitrogen-depleted conditions. Transcripts of genes encoding Photosystem I and II were increased by hik8 overexpression under nitrogen-replete conditions. Nitrogen starvation triggers increase in amino acids but the magnitude of the increase in several amino acids was diminished by hik8 overexpression. These genetic data indicate that Hik8 regulates the photosynthetic electron transport, which in turn alters primary metabolism during nitrogen starvation in this cyanobacterium.
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Affiliation(s)
- Ayuko Kuwahara
- RIKEN Center for Sustainable Resource ScienceYokohama, Japan
| | - Satomi Arisaka
- Department of Agricultural Chemistry, School of Agriculture, Meiji UniversityKawasaki, Japan
| | - Masahiro Takeya
- Department of Agricultural Chemistry, School of Agriculture, Meiji UniversityKawasaki, Japan
| | - Hiroko Iijima
- Department of Agricultural Chemistry, School of Agriculture, Meiji UniversityKawasaki, Japan
| | | | - Takashi Osanai
- RIKEN Center for Sustainable Resource ScienceYokohama, Japan
- Department of Agricultural Chemistry, School of Agriculture, Meiji UniversityKawasaki, Japan
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Cardona T. A fresh look at the evolution and diversification of photochemical reaction centers. PHOTOSYNTHESIS RESEARCH 2015; 126:111-34. [PMID: 25512103 PMCID: PMC4582080 DOI: 10.1007/s11120-014-0065-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 12/05/2014] [Indexed: 05/18/2023]
Abstract
In this review, I reexamine the origin and diversification of photochemical reaction centers based on the known phylogenetic relations of the core subunits, and with the aid of sequence and structural alignments. I show, for example, that the protein folds at the C-terminus of the D1 and D2 subunits of Photosystem II, which are essential for the coordination of the water-oxidizing complex, were already in place in the most ancestral Type II reaction center subunit. I then evaluate the evolution of reaction centers in the context of the rise and expansion of the different groups of bacteria based on recent large-scale phylogenetic analyses. I find that the Heliobacteriaceae family of Firmicutes appears to be the earliest branching of the known groups of phototrophic bacteria; however, the origin of photochemical reaction centers and chlorophyll synthesis cannot be placed in this group. Moreover, it becomes evident that the Acidobacteria and the Proteobacteria shared a more recent common phototrophic ancestor, and this is also likely for the Chloroflexi and the Cyanobacteria. Finally, I argue that the discrepancies among the phylogenies of the reaction center proteins, chlorophyll synthesis enzymes, and the species tree of bacteria are best explained if both types of photochemical reaction centers evolved before the diversification of the known phyla of phototrophic bacteria. The primordial phototrophic ancestor must have had both Type I and Type II reaction centers.
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Affiliation(s)
- Tanai Cardona
- Department of Life Sciences, Imperial College London, Exhibition Road, London, SW7 2AZ, UK.
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Chukhutsina V, Bersanini L, Aro EM, van Amerongen H. Cyanobacterial flv4-2 Operon-Encoded Proteins Optimize Light Harvesting and Charge Separation in Photosystem II. MOLECULAR PLANT 2015; 8:747-61. [PMID: 25704162 DOI: 10.1016/j.molp.2014.12.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 12/09/2014] [Accepted: 12/21/2014] [Indexed: 05/11/2023]
Abstract
Photosystem II (PSII) complexes drive the water-splitting reaction necessary to transform sunlight into chemical energy. However, too much light can damage and disrupt PSII. In cyanobacteria, the flv4-2 operon encodes three proteins (Flv2, Flv4, and Sll0218), which safeguard PSII activity under air-level CO2 and in high light conditions. However, the exact mechanism of action of these proteins has not been clarified yet. We demonstrate that the PSII electron transfer properties are influenced by the flv4-2 operon-encoded proteins. Accelerated secondary charge separation kinetics was observed upon expression/overexpression of the flv4-2 operon. This is likely induced by docking of the Flv2/Flv4 heterodimer in the vicinity of the QB pocket of PSII, which, in turn, increases the QB redox potential and consequently stabilizes forward electron transfer. The alternative electron transfer route constituted by Flv2/Flv4 sequesters electrons from QB(-) guaranteeing the dissipation of excess excitation energy in PSII under stressful conditions. In addition, we demonstrate that in the absence of the flv4-2 operon-encoded proteins, about 20% of the phycobilisome antenna becomes detached from the reaction centers, thus decreasing light harvesting. Phycobilisome detachment is a consequence of a decreased relative content of PSII dimers, a feature observed in the absence of the Sll0218 protein.
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Affiliation(s)
- Volha Chukhutsina
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, The Netherlands; MicroSpectroscopy Centre, Wageningen University, 6703HA Wageningen, The Netherlands; BioSolarCells, P.O. Box 98, 6700AB Wageningen, The Netherlands
| | - Luca Bersanini
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Eva-Mari Aro
- Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, The Netherlands; MicroSpectroscopy Centre, Wageningen University, 6703HA Wageningen, The Netherlands; BioSolarCells, P.O. Box 98, 6700AB Wageningen, The Netherlands.
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Cardona T, Murray JW, Rutherford AW. Origin and Evolution of Water Oxidation before the Last Common Ancestor of the Cyanobacteria. Mol Biol Evol 2015; 32:1310-28. [PMID: 25657330 PMCID: PMC4408414 DOI: 10.1093/molbev/msv024] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Photosystem II, the water oxidizing enzyme, altered the course of evolution by filling the atmosphere with oxygen. Here, we reconstruct the origin and evolution of water oxidation at an unprecedented level of detail by studying the phylogeny of all D1 subunits, the main protein coordinating the water oxidizing cluster (Mn4CaO5) of Photosystem II. We show that D1 exists in several forms making well-defined clades, some of which could have evolved before the origin of water oxidation and presenting many atypical characteristics. The most ancient form is found in the genome of Gloeobacter kilaueensis JS-1 and this has a C-terminus with a higher sequence identity to D2 than to any other D1. Two other groups of early evolving D1 correspond to those expressed under prolonged far-red illumination and in darkness. These atypical D1 forms are characterized by a dramatically different Mn4CaO5 binding site and a Photosystem II containing such a site may assemble an unconventional metal cluster. The first D1 forms with a full set of ligands to the Mn4CaO5 cluster are grouped with D1 proteins expressed only under low oxygen concentrations and the latest evolving form is the dominant type of D1 found in all cyanobacteria and plastids. In addition, we show that the plastid ancestor had a D1 more similar to those in early branching Synechococcus. We suggest each one of these forms of D1 originated from transitional forms at different stages toward the innovation and optimization of water oxidation before the last common ancestor of all known cyanobacteria.
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Affiliation(s)
- Tanai Cardona
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - James W Murray
- Department of Life Sciences, Imperial College London, London, United Kingdom
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Chu HA, Chiu YF. The Roles of Cytochrome b 559 in Assembly and Photoprotection of Photosystem II Revealed by Site-Directed Mutagenesis Studies. FRONTIERS IN PLANT SCIENCE 2015; 6:1261. [PMID: 26793230 PMCID: PMC4709441 DOI: 10.3389/fpls.2015.01261] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/24/2015] [Indexed: 05/05/2023]
Abstract
Cytochrome b 559 (Cyt b 559) is one of the essential components of the Photosystem II reaction center (PSII). Despite recent accomplishments in understanding the structure and function of PSII, the exact physiological function of Cyt b 559 remains unclear. Cyt b 559 is not involved in the primary electron transfer pathway in PSII but may participate in secondary electron transfer pathways that protect PSII against photoinhibition. Site-directed mutagenesis studies combined with spectroscopic and functional analysis have been used to characterize Cyt b 559 mutant strains and their mutant PSII complex in higher plants, green algae, and cyanobacteria. These integrated studies have provided important in vivo evidence for possible physiological roles of Cyt b 559 in the assembly and stability of PSII, protecting PSII against photoinhibition, and modulating photosynthetic light harvesting. This mini-review presents an overview of recent important progress in site-directed mutagenesis studies of Cyt b 559 and implications for revealing the physiological functions of Cyt b 559 in PSII.
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47
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The D1-173 amino acid is a structural determinant of the critical interaction between D1-Tyr161 (Tyr Z ) and D1-His190 in Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1922-1931. [DOI: 10.1016/j.bbabio.2014.08.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/20/2014] [Accepted: 08/26/2014] [Indexed: 02/01/2023]
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Sugiura M, Boussac A. Variants of photosystem II D1 protein in Thermosynechococcus elongatus. RESEARCH ON CHEMICAL INTERMEDIATES 2014. [DOI: 10.1007/s11164-014-1828-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Billis K, Billini M, Tripp HJ, Kyrpides NC, Mavromatis K. Comparative transcriptomics between Synechococcus PCC 7942 and Synechocystis PCC 6803 provide insights into mechanisms of stress acclimation. PLoS One 2014; 9:e109738. [PMID: 25340743 PMCID: PMC4207680 DOI: 10.1371/journal.pone.0109738] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 08/13/2014] [Indexed: 12/13/2022] Open
Abstract
Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803 are model cyanobacteria from which the metabolism and adaptive responses of other cyanobacteria are inferred. Using stranded and 5' enriched libraries, we measured the gene expression response of cells transferred from reference conditions to stress conditions of decreased inorganic carbon, increased salinity, increased pH, and decreased illumination at 1-h and 24-h after transfer. We found that the specific responses of the two strains were by no means identical. Transcriptome profiles allowed us to improve the structural annotation of the genome i.e. identify possible missed genes (including anti-sense), alter gene coordinates and determine transcriptional units (operons). Finally, we predicted associations between proteins of unknown function and biochemical pathways by revealing proteins of known functions that are co-regulated with the unknowns. Future studies of these model organisms will benefit from the cataloging of their responses to environmentally relevant stresses, and improvements in their genome annotations found here.
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Affiliation(s)
- Konstantinos Billis
- Microbial Genome and Metagenome Program, DOE-Joint Genome Institute, Walnut Creek, California, United States of America
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- Department of Genetics, Development and Molecular Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Maria Billini
- Microbial Genome and Metagenome Program, DOE-Joint Genome Institute, Walnut Creek, California, United States of America
- Group of Prokaryotic Cell Biology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Faculty of Biology, Philipps-Universität, Marburg, Germany
| | - H. James Tripp
- Microbial Genome and Metagenome Program, DOE-Joint Genome Institute, Walnut Creek, California, United States of America
| | - Nikos C. Kyrpides
- Microbial Genome and Metagenome Program, DOE-Joint Genome Institute, Walnut Creek, California, United States of America
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Konstantinos Mavromatis
- Microbial Genome and Metagenome Program, DOE-Joint Genome Institute, Walnut Creek, California, United States of America
- Computational Biology Group, Celgene Corp, San Francisco, California, United States of America
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Cationic screening of charged surface groups (carboxylates) affects electron transfer steps in photosystem-II water oxidation and quinone reduction. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1625-34. [DOI: 10.1016/j.bbabio.2014.07.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 07/14/2014] [Accepted: 07/16/2014] [Indexed: 11/23/2022]
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