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Kang DK, Kim SH, Sohn JH, Sung BH. Insights into Enzyme Reactions with Redox Cofactors in Biological Conversion of CO 2. J Microbiol Biotechnol 2023; 33:1403-1411. [PMID: 37482811 DOI: 10.4014/jmb.2306.06005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 07/25/2023]
Abstract
Carbon dioxide (CO2) is the most abundant component of greenhouse gases (GHGs) and directly creates environmental issues such as global warming and climate change. Carbon capture and storage have been proposed mainly to solve the problem of increasing CO2 concentration in the atmosphere; however, more emphasis has recently been placed on its use. Among the many methods of using CO2, one of the key environmentally friendly technologies involves biologically converting CO2 into other organic substances such as biofuels, chemicals, and biomass via various metabolic pathways. Although an efficient biocatalyst for industrial applications has not yet been developed, biological CO2 conversion is the needed direction. To this end, this review briefly summarizes seven known natural CO2 fixation pathways according to carbon number and describes recent studies in which natural CO2 assimilation systems have been applied to heterogeneous in vivo and in vitro systems. In addition, studies on the production of methanol through the reduction of CO2 are introduced. The importance of redox cofactors, which are often overlooked in the CO2 assimilation reaction by enzymes, is presented; methods for their recycling are proposed. Although more research is needed, biological CO2 conversion will play an important role in reducing GHG emissions and producing useful substances in terms of resource cycling.
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Affiliation(s)
- Du-Kyeong Kang
- Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
- Department of Biosystems and Bioengineering, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Seung-Hwa Kim
- Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
- Department of Biosystems and Bioengineering, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Jung-Hoon Sohn
- Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
- Department of Biosystems and Bioengineering, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Bong Hyun Sung
- Synthetic Biology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
- Department of Biosystems and Bioengineering, Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea
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2
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Chapman A, Ertekin E, Kubota M, Nagao A, Bertsch K, Macadre A, Tsuchiyama T, Masamura T, Takaki S, Komoda R, Dadfarnia M, Somerday B, Staykov AT, Sugimura J, Sawae Y, Morita T, Tanaka H, Yagi K, Niste V, Saravanan P, Onitsuka S, Yoon KS, Ogo S, Matsushima T, Tumen-Ulzii G, Klotz D, Nguyen DH, Harrington G, Adachi C, Matsumoto H, Kwati L, Takahashi Y, Kosem N, Ishihara T, Yamauchi M, Saha BB, Islam MA, Miyawaki J, Sivasankaran H, Kohno M, Fujikawa S, Selyanchyn R, Tsuji T, Higashi Y, Kirchheim R, Sofronis P. Achieving a Carbon Neutral Future through Advanced Functional Materials and Technologies. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2022. [DOI: 10.1246/bcsj.20210323] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Andrew Chapman
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Elif Ertekin
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Illinois, USA
| | - Masanobu Kubota
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Akihide Nagao
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Kaila Bertsch
- Lawrence Livermore National Laboratory, California, USA
| | - Arnaud Macadre
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Yamaguchi University, Yamaguchi, Japan
| | - Toshihiro Tsuchiyama
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Materials Science and Engineering, Kyushu University, Fukuoka, Japan
| | - Takuro Masamura
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Materials Science and Engineering, Kyushu University, Fukuoka, Japan
| | - Setsuo Takaki
- Netsuren Co., Ltd., Hyogo, Japan
- Emeritus Professor, Kyushu University, Fukuoka, Japan
| | - Ryosuke Komoda
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Fukuoka University, Fukuoka, Japan
| | - Mohsen Dadfarnia
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Seattle University, Washington, USA
| | - Brian Somerday
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Illinois, USA
- Somerday Consulting LLC, Pennsylvania, USA
| | - Alexander Tsekov Staykov
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Joichi Sugimura
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Research Center for Hydrogen Industrial Use and Storage, Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Fukuoka University, Fukuoka, Japan
| | - Yoshinori Sawae
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Fukuoka University, Fukuoka, Japan
| | - Takehiro Morita
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Fukuoka University, Fukuoka, Japan
| | - Hiroyoshi Tanaka
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Research Center for Hydrogen Industrial Use and Storage, Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Fukuoka University, Fukuoka, Japan
| | - Kazuyuki Yagi
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Research Center for Hydrogen Industrial Use and Storage, Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Fukuoka University, Fukuoka, Japan
| | | | - Prabakaran Saravanan
- Department of Mechanical Engineering, Birla Institute of Technology & Science - Pilani, Hyderabad, Telangana, India
| | - Shugo Onitsuka
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Ki-Seok Yoon
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Seiji Ogo
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Toshinori Matsushima
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Ganbaatar Tumen-Ulzii
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Dino Klotz
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Dinh Hoa Nguyen
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - George Harrington
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Chihaya Adachi
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Hiroshige Matsumoto
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Leonard Kwati
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Yukina Takahashi
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Nuttavut Kosem
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Tatsumi Ishihara
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Miho Yamauchi
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Bidyut Baran Saha
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Md. Amirul Islam
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Jin Miyawaki
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Harish Sivasankaran
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Masamichi Kohno
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Shigenori Fujikawa
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Roman Selyanchyn
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Takeshi Tsuji
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Yukihiro Higashi
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
| | - Reiner Kirchheim
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Institute of Materials Physics, University of Gottingen, Germany
| | - Petros Sofronis
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, Fukuoka, Japan
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Illinois, USA
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3
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Li B, Steindel P, Haddad N, Elliott SJ. Maximizing (Electro)catalytic CO 2 Reduction with a Ferredoxin-Based Reduction Potential Gradient. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Bin Li
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Phillip Steindel
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Narmien Haddad
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
| | - Sean J. Elliott
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States
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4
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Rubredoxin from the green sulfur bacterium Chlorobaculum tepidum donates a redox equivalent to the flavodiiron protein in an NAD(P)H dependent manner via ferredoxin-NAD(P) + oxidoreductase. Arch Microbiol 2020; 203:799-808. [PMID: 33051772 DOI: 10.1007/s00203-020-02079-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 10/23/2022]
Abstract
The green sulfur bacterium, Chlorobaculum tepidum, is an anaerobic photoautotroph that performs anoxygenic photosynthesis. Although genes encoding rubredoxin (Rd) and a putative flavodiiron protein (FDP) were reported in the genome, a gene encoding putative NADH-Rd oxidoreductase is not identified. In this work, we expressed and purified the recombinant Rd and FDP and confirmed dioxygen reductase activity in the presence of ferredoxin-NAD(P)+ oxidoreductase (FNR). FNR from C. tepidum and Bacillus subtilis catalyzed the reduction of Rd at rates comparable to those reported for NADH-Rd oxidoreductases. Also, we observed substrate inhibition at high concentrations of NADPH similar to that observed with ferredoxins. In the presence of NADPH, B. subtilis FNR and Rd, FDP promoted dioxygen reduction at rates comparable to those reported for other bacterial FDPs. Taken together, our results suggest that Rd and FDP participate in the reduction of dioxygen in C. tepidum and that FNR can promote the reduction of Rd in this bacterium.
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5
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Role of N, N-Dimethylglycine and Its Catabolism to Sarcosine in Chromohalobacter salexigens DSM 3043. Appl Environ Microbiol 2020; 86:AEM.01186-20. [PMID: 32631860 DOI: 10.1128/aem.01186-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/28/2020] [Indexed: 11/20/2022] Open
Abstract
Chromohalobacter salexigens DSM 3043 can grow on N,N-dimethylglycine (DMG) as the sole C, N, and energy source and utilize sarcosine as the sole N source under aerobic conditions. However, little is known about the genes and enzymes involved in the conversion of DMG to sarcosine in this strain. In the present study, gene disruption and complementation assays indicated that the csal_0990, csal_0991, csal_0992, and csal_0993 genes are responsible for DMG degradation to sarcosine. The csal_0990 gene heterologously expressed in Escherichia coli was proven to encode an unusual DMG dehydrogenase (DMGDH). The enzyme, existing as a monomer of 79 kDa with a noncovalently bound flavin adenine dinucleotide, utilized both DMG and sarcosine as substrates and exhibited dual coenzyme specificity, preferring NAD+ to NADP+ The optimum pH and temperature of enzyme activity were determined to be 7.0 and 60°C, respectively. Kinetic parameters of the enzyme toward its substrates were determined accordingly. Under high-salinity conditions, the presence of DMG inhibited growth of the wild type and induced the production and accumulation of trehalose and glucosylglycerate intracellularly. Moreover, exogenous addition of DMG significantly improved the growth rates of the four DMG- mutants (Δcsal_0990, Δcsal_0991, Δcsal_0992, and Δcsal_0993) incubated at 37°C in S-M63 synthetic medium with sarcosine as the sole N source. 13C nuclear magnetic resonance (13C-NMR) experiments revealed that not only ectoine, glutamate, and N-acetyl-2,4-diaminobutyrate but also glycine betaine (GB), DMG, sarcosine, trehalose, and glucosylglycerate are accumulated intracellularly in the four mutants.IMPORTANCE Although N,N-dimethylglycine (DMG) dehydrogenase (DMGDH) activity was detected in cell extracts of microorganisms, the genes encoding microbial DMGDHs have not been determined until now. In addition, to our knowledge, the physiological role of DMG in moderate halophiles has never been investigated. In this study, we identified the genes involved in DMG degradation to sarcosine, characterized an unusual DMGDH, and investigated the role of DMG in Chromohalobacter salexigens DSM 3043 and its mutants. Our results suggested that the conversion of DMG to sarcosine is accompanied by intramolecular delivery of electrons in DMGDH and intermolecular electron transfer between DMGDH and other electron acceptors. Moreover, an unidentified methyltransferase catalyzing the production of glycine betaine (GB) from DMG but sharing no homology with the reported sarcosine DMG methyltransferases was predicted to be present in the cells. The results of this study expand our understanding of the physiological role of DMG and its catabolism to sarcosine in C. salexigens.
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6
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Walters KA, Golbeck JH. Designing a modified clostridial 2[4Fe-4S] ferredoxin as a redox coupler to directly link photosystem I with a Pt nanoparticle. PHOTOSYNTHESIS RESEARCH 2020; 143:165-181. [PMID: 31643016 DOI: 10.1007/s11120-019-00679-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/01/2019] [Indexed: 06/10/2023]
Abstract
A methodology previously developed in our laboratory utilized an aliphatic hydrocarbon terminated by thiol groups to tether two redox proteins, i.e., the [4Fe-4S] cluster FB of photosystem I (PS I) and the distal [4Fe-4S] cluster of a [FeFe]-hydrogenase, to create a biohybrid dihydrogen-generating complex. These studies guided the design of a modified 2[4Fe-4S] cluster ferredoxin from Clostridium pasteurianum (CpFd) containing two externally facing cysteine residues in close proximity to each [4Fe-4S] cluster that replaces the aliphatic hydrocarbon dithiol tether. The advantage of using a protein is the potential to create a coupled dihydrogen-generating system in vivo. The wild-type CpFdWT and variants CpFdS11C/D40C, CpFdP20C/P49C, CpFdD7S/D36S, CpFdS11C/D40C/D7S/D36S and CpFdP20C/P49C/D7S/D36S were expressed in Escherichia coli and found to contain ~ 8 Fe and ~ 8 S atoms. The absorption spectra of the wild-type and CpFd variants displayed a peak centered at ~ 390 nm characteristic of a S → Fe charge transfer band that diminishes upon reduction with Na-dithionite. Low-temperature X-band EPR studies of the Na-dithionite-reduced wild-type and CpFd variants showed a complex spectrum indicative of two magnetically coupled [4Fe-4S]1+ clusters. EPR-monitored redox titrations of CpFdWT, CpFdD7S/D36S, CpFdS11C/D40C, CpFdP20C/P49C, CpFdS11C/D40C/D7S/D36S and CpFdP20C/P49C/D7S/D36S revealed redox potentials of - 412 ± 8 mV, - 395 ± 4 mV, - 408 ± 7 mV, - 426 ± 11 mV, - 384 ± 4 mV and - 423 ± 4 mV, respectively. The in vitro PS I-CpFdS11C/D40C/D7S/D36S-Pt nanoparticle complex was the highest performer, generating dihydrogen at a rate of 3.25 μmol H2 mg Chl-1 h-1 or 278.8 mol H2 mol PS I-1 h-1 under continuous illumination.
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Affiliation(s)
- Karim A Walters
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, S328 Frear Building, University Park, PA, 16802, USA
| | - John H Golbeck
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, S328 Frear Building, University Park, PA, 16802, USA.
- Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
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7
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Maiocco SJ, Arcinas AJ, Booker SJ, Elliott SJ. Parsing redox potentials of five ferredoxins found within Thermotoga maritima. Protein Sci 2020; 28:257-266. [PMID: 30418685 DOI: 10.1002/pro.3547] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 11/01/2018] [Accepted: 11/01/2018] [Indexed: 01/15/2023]
Abstract
Most organisms contain multiple soluble protein-based redox carriers such as members of the ferredoxin (Fd) family, that contain one or more iron-sulfur clusters. The potential redundancy of Fd proteins is poorly understood, particularly in connection to the ability of Fd proteins to deliver reducing equivalents to members of the "radical SAM," or S-adenosylmethionine radical enzyme (ARE) superfamily, where the activity of all known AREs requires that an essential iron-sulfur cluster bound by the enzyme be reduced to the catalytically relevant [Fe4 S4 ]1+ oxidation state. As it is still unclear whether a single Fd in a given organism is specific to individual redox partners, we have examined the five Fd proteins found within Thermotoga maritima via direct electrochemistry, to compare them in a side-by-side fashion for the first time. While a single [Fe4 S4 ]-cluster bearing Fd (TM0927) has a potential of -420 mV, the other four 2x[Fe4 S4 ]-bearing Fds (TM1175, TM1289, TM1533, and TM1815) have potentials that vary significantly, including cases where the two clusters of the same Fd are essentially coincident (e.g., TM1175) and those where the potentials are well separate (TM1815).
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Affiliation(s)
| | - Arthur J Arcinas
- Department of Biochemistry and Molecular, The Pennsylvania State University, University Park, Pennsylvania, 16802
| | - Squire J Booker
- Department of Biochemistry and Molecular, The Pennsylvania State University, University Park, Pennsylvania, 16802.,Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, 16802.,Howard Hughes Medical Institute, The Pennsylvania State University, University Park, Pennsylvania, 16802
| | - Sean J Elliott
- Department of Chemistry, Boston University, Boston, Massachusetts, 02215
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8
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Bertsova YV, Mamedov MD, Bogachev AV. Na+-Translocating Ferredoxin:NAD+ Oxidoreductase Is a Component of Photosynthetic Electron Transport Chain in Green Sulfur Bacteria. BIOCHEMISTRY (MOSCOW) 2019; 84:1403-1410. [PMID: 31760926 DOI: 10.1134/s0006297919110142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Genomes of photoautotrophic organisms containing type I photosynthetic reaction center were searched for the rnf genes encoding Na+-translocating ferredoxin:NAD+ oxidoreductase (RNF). These genes were absent in heliobacteria, cyanobacteria, algae, and plants; however, genomes of many green sulfur bacteria (especially marine ones) were found to contain the full rnf operon. Analysis of RNA isolated from the marine green sulfur bacterium Chlorobium phaeovibrioides revealed a high level of rnf expression. It was found that the activity of Na+-dependent flavodoxin:NAD+ oxidoreductase detected in the membrane fraction of Chl. phaeovibrioides was absent in the membrane fraction of the freshwater green sulfur bacterium Chlorobaculum limnaeum, which is closely related to Chl. phaeovibrioides but whose genome lacks the rnf genes. Illumination of the membrane fraction of Chl. phaeovibrioides but not of Cba. limnaeum resulted in the light-induced NAD+ reduction. Based on the obtained data, we concluded that in some green sulfur bacteria, RNF may be involved in the NADH formation that should increase the efficiency of light energy conservation in these microorganisms and can serve as the first example of the use of Na+ energetics in photosynthetic electron transport chains.
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Affiliation(s)
- Y V Bertsova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - M D Mamedov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - A V Bogachev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234, Russia.
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Bertsova YV, Kulik LV, Mamedov MD, Baykov AA, Bogachev AV. Flavodoxin with an air-stable flavin semiquinone in a green sulfur bacterium. PHOTOSYNTHESIS RESEARCH 2019; 142:127-136. [PMID: 31302833 DOI: 10.1007/s11120-019-00658-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/04/2019] [Indexed: 06/10/2023]
Abstract
Flavodoxins are small proteins with a non-covalently bound FMN that can accept two electrons and accordingly adopt three redox states: oxidized (quinone), one-electron reduced (semiquinone), and two-electron reduced (quinol). In iron-deficient cyanobacteria and algae, flavodoxin can substitute for ferredoxin as the electron carrier in the photosynthetic electron transport chain. Here, we demonstrate a similar function for flavodoxin from the green sulfur bacterium Chlorobium phaeovibrioides (cp-Fld). The expression of the cp-Fld gene, found in a close proximity with the genes for other proteins associated with iron transport and storage, increased in a low-iron medium. cp-Fld produced in Escherichia coli exhibited the optical, ERP, and electron-nuclear double resonance spectra that were similar to those of known flavodoxins. However, unlike all other flavodoxins, cp-Fld exhibited unprecedented stability of FMN semiquinone to oxidation by air and difference in midpoint redox potentials for the quinone-semiquinone and semiquinone-quinol couples (- 110 and - 530 mV, respectively). cp-Fld could be reduced by pyruvate:ferredoxin oxidoreductase found in the membrane-free extract of Chl. phaeovibrioides cells and photo-reduced by the photosynthetic reaction center found in membrane vesicles from these cells. The green sulfur bacterium Chl. phaeovibrioides appears thus to be a new type of the photosynthetic organisms that can use flavodoxin as an alternative electron carrier to cope with iron deficiency.
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Affiliation(s)
- Yulia V Bertsova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Leonid V Kulik
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, Russia, 630090
- Novosibirsk State University, Novosibirsk, Russia, 630090
| | - Mahir D Mamedov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Alexander A Baykov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Alexander V Bogachev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119234.
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10
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Witt A, Pozzi R, Diesch S, Hädicke O, Grammel H. New light on ancient enzymes –
in vitro
CO
2
Fixation by Pyruvate Synthase of
Desulfovibrio africanus
and
Sulfolobus acidocaldarius. FEBS J 2019; 286:4494-4508. [DOI: 10.1111/febs.14981] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 05/13/2019] [Accepted: 07/02/2019] [Indexed: 01/09/2023]
Affiliation(s)
- Andreas Witt
- Hochschule Biberach University of Applied Science Biberach Germany
| | - Roberta Pozzi
- Hochschule Biberach University of Applied Science Biberach Germany
| | - Stephan Diesch
- Hochschule Biberach University of Applied Science Biberach Germany
| | - Oliver Hädicke
- Max Planck Institute for Dynamics of Complex Technical Systems Magdeburg Germany
| | - Hartmut Grammel
- Hochschule Biberach University of Applied Science Biberach Germany
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11
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Chen PYT, Li B, Drennan CL, Elliott SJ. A reverse TCA cycle 2-oxoacid:ferredoxin oxidoreductase that makes C-C bonds from CO 2. JOULE 2019; 3:595-611. [PMID: 31080943 PMCID: PMC6508887 DOI: 10.1016/j.joule.2018.12.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
2-oxoglutarate:ferredoxin oxidoreductase (OGOR) is a thiamine pyrophosphate (TPP) and [4Fe-4S] cluster-dependent enzyme from the reductive tricarboxylic acid (rTCA) cycle that fixes CO2 to succinyl-CoA, forming 2-oxoglutarate and CoA. Here we report an OGOR from the rTCA cycle of Magnetococcus marinus MC-1, along with all three potential ferredoxin (Fd) redox partners. We demonstrate MmOGOR operates bidirectionally (both CO2-fixing and 2-oxoglutarate oxidizing), and that only one Fd (MmFd1) supports efficient catalysis. Our 1.94-Å and 2.80-Å resolution crystal structures of native and substrate-bound forms of MmOGOR reveal the determinants of substrate specificity and CoA-binding in an OGOR, and illuminate the [4Fe-4S] cluster environment, portraying the electronic conduit allowing MmFd1 to be wired to the bound-TPP. Structural and biochemical data further identify Glu45α as a mobile residue that impacts catalytic bias toward CO2-fixation although it makes no direct contact with TPP-bound intermediates, indicating that reaction directionality can be tuned by second layer interactions. (149 of 150 words limit).
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Affiliation(s)
| | - Bin Li
- Department of Chemistry, Boston University, Boston, MA 02215
| | - Catherine L. Drennan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139
- Bio-inspired Solar Energy Program, Canadian Institute for Advanced Research, Toronto, Canada
| | - Sean J. Elliott
- Department of Chemistry, Boston University, Boston, MA 02215
- Lead contact
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12
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Buchanan BB, Sirevåg R, Fuchs G, Ivanovsky RN, Igarashi Y, Ishii M, Tabita FR, Berg IA. The Arnon-Buchanan cycle: a retrospective, 1966-2016. PHOTOSYNTHESIS RESEARCH 2017; 134:117-131. [PMID: 29019085 DOI: 10.1007/s11120-017-0429-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 08/03/2017] [Indexed: 06/07/2023]
Abstract
For the first decade following its description in 1954, the Calvin-Benson cycle was considered the sole pathway of autotrophic CO2 assimilation. In the early 1960s, experiments with fermentative bacteria uncovered reactions that challenged this concept. Ferredoxin was found to donate electrons directly for the reductive fixation of CO2 into alpha-keto acids via reactions considered irreversible. Thus, pyruvate and alpha-ketoglutarate could be synthesized from CO2, reduced ferredoxin and acetyl-CoA or succinyl-CoA, respectively. This work opened the door to the discovery that reduced ferredoxin could drive the Krebs citric acid cycle in reverse, converting the pathway from its historical role in carbohydrate breakdown to one fixing CO2. Originally uncovered in photosynthetic green sulfur bacteria, the Arnon-Buchanan cycle has since been divorced from light and shown to function in a variety of anaerobic chemoautotrophs. In this retrospective, colleagues who worked on the cycle at its inception in 1966 and those presently working in the field trace its development from a controversial reception to its present-day inclusion in textbooks. This pathway is now well established in major groups of chemoautotrophic bacteria, instead of the Calvin-Benson cycle, and is increasingly referred to as the Arnon-Buchanan cycle. In this retrospective, separate sections have been written by the authors indicated. Bob Buchanan wrote the abstract and the concluding comments.
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Affiliation(s)
- Bob B Buchanan
- Department of Plant & Microbial Biology, University of California, 111 Koshland Hall, Berkeley, CA, 94720, USA.
| | - Reidun Sirevåg
- Department of Biosciences, University of Oslo, Blindern, Box 1066, 0316, Oslo, Norway
| | - Georg Fuchs
- Mikrobiologie, Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Ruslan N Ivanovsky
- Department of Microbiology, M.V. Lomonosov Moscow State University, 1/12 Lenin's Hills, Moscow, Russia, 119991
| | - Yasuo Igarashi
- Southwest University, Chongqing, 2 Tiansheng Rd, Beibei Qu, Chongqing Shi, 400700, China
| | - Masaharu Ishii
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - F Robert Tabita
- Department of Microbiology, The Ohio State University, 484 West 12th Avenue, Columbus, OH, 43210, USA
| | - Ivan A Berg
- Institute for Molecular Microbiology and Biotechnology, University of Münster, Corrensstr. 3, 48149, Münster, Germany
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Takenaka M, Yoon KS, Matsumoto T, Ogo S. Acetyl-CoA production by encapsulated pyruvate ferredoxin oxidoreductase in alginate hydrogels. BIORESOURCE TECHNOLOGY 2017; 227:279-285. [PMID: 28040649 DOI: 10.1016/j.biortech.2016.12.051] [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: 10/16/2016] [Revised: 12/10/2016] [Accepted: 12/12/2016] [Indexed: 05/08/2023]
Abstract
Pyruvate ferredoxin oxidoreductase from Citrobacter sp. S-77 (PFORS77) was purified in order to develop a method for acetyl-CoA production. Although the purified PFORS77 showed high O2-sensitivity, the activity could be remarkably stabilized in anaerobic conditions. PFORS77 was effectively immobilized on ceramic hydroxyapatite (PFORS77-HA) with an efficiency of more than 96%, however, after encapsulation of PFORS77-HA in alginate, the rate of catalytic acetyl-CoA production was highly reduced to 36% when compared to that of the free enzyme. However, the operational stability of the PFORS77-HA in alginate hydrogels was remarkable, retaining over 68% initial activity even after ten repeated cycles. The results suggested that the PFORS77-HA hydrogels have a high potential for biotechnological application.
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Affiliation(s)
- Makoto Takenaka
- International Institute for Carbon-Neutral Energy Research (WPI-I(2)CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ki-Seok Yoon
- International Institute for Carbon-Neutral Energy Research (WPI-I(2)CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; Centre for Small Molecule Energy, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Takahiro Matsumoto
- International Institute for Carbon-Neutral Energy Research (WPI-I(2)CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; Centre for Small Molecule Energy, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Seiji Ogo
- International Institute for Carbon-Neutral Energy Research (WPI-I(2)CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; Centre for Small Molecule Energy, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
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Thweatt JL, Ferlez BH, Golbeck JH, Bryant DA. BciD Is a Radical S-Adenosyl-l-methionine (SAM) Enzyme That Completes Bacteriochlorophyllide e Biosynthesis by Oxidizing a Methyl Group into a Formyl Group at C-7. J Biol Chem 2016; 292:1361-1373. [PMID: 27994052 DOI: 10.1074/jbc.m116.767665] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/12/2016] [Indexed: 01/05/2023] Open
Abstract
Green bacteria are chlorophotorophs that synthesize bacteriochlorophyll (BChl) c, d, or e, which assemble into supramolecular, nanotubular structures in large light-harvesting structures called chlorosomes. The biosynthetic pathways of these chlorophylls are known except for one reaction. Null mutants of bciD, which encodes a putative radical S-adenosyl-l-methionine (SAM) protein, are unable to synthesize BChl e but accumulate BChl c; however, it is unknown whether BciD is sufficient to convert BChl c (or its precursor, bacteriochlorophyllide (BChlide) c) into BChl e (or BChlide e). To determine the function of BciD, we expressed the bciD gene of Chlorobaculum limnaeum strain DSMZ 1677T in Escherichia coli and purified the enzyme under anoxic conditions. Electron paramagnetic resonance spectroscopy of BciD indicated that it contains a single [4Fe-4S] cluster. In assays containing SAM, BChlide c or d, and sodium dithionite, BciD catalyzed the conversion of SAM into 5'-deoxyadenosine and BChlide c or d into BChlide e or f, respectively. Our analyses also identified intermediates that are proposed to be 71-OH-BChlide c and d Thus, BciD is a radical SAM enzyme that converts the methyl group of BChlide c or d into the formyl group of BChlide e or f This probably occurs by a mechanism involving consecutive hydroxylation reactions of the C-7 methyl group to form a geminal diol intermediate, which spontaneously dehydrates to produce the final products, BChlide e or BChlide f The demonstration that BciD is sufficient to catalyze the conversion of BChlide c into BChlide e completes the biosynthetic pathways for all "Chlorobium chlorophylls."
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Affiliation(s)
| | - Bryan H Ferlez
- From the Departments of Biochemistry and Molecular Biology and
| | - John H Golbeck
- From the Departments of Biochemistry and Molecular Biology and.,Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Donald A Bryant
- From the Departments of Biochemistry and Molecular Biology and .,the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
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Birrell JA, Wrede K, Pawlak K, Rodriguez-Maciá P, Rüdiger O, Reijerse EJ, Lubitz W. Artificial Maturation of the Highly Active Heterodimeric [FeFe] Hydrogenase from Desulfovibrio desulfuricans
ATCC 7757. Isr J Chem 2016. [DOI: 10.1002/ijch.201600035] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- James A. Birrell
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Kathrin Wrede
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Krzysztof Pawlak
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Patricia Rodriguez-Maciá
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Olaf Rüdiger
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Edward J. Reijerse
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion; Stiftstraße 34-36 D-45470 Mülheim an der Ruhr Germany
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16
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Li B, Elliott SJ. The Catalytic Bias of 2-Oxoacid:ferredoxin Oxidoreductase in CO2: evolution and reduction through a ferredoxin-mediated electrocatalytic assay. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.02.119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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Klatt CG, Liu Z, Ludwig M, Kühl M, Jensen SI, Bryant DA, Ward DM. Temporal metatranscriptomic patterning in phototrophic Chloroflexi inhabiting a microbial mat in a geothermal spring. THE ISME JOURNAL 2013; 7:1775-89. [PMID: 23575369 PMCID: PMC3749495 DOI: 10.1038/ismej.2013.52] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 02/10/2013] [Accepted: 02/13/2013] [Indexed: 11/09/2022]
Abstract
Filamentous anoxygenic phototrophs (FAPs) are abundant members of microbial mat communities inhabiting neutral and alkaline geothermal springs. Natural populations of FAPs related to Chloroflexus spp. and Roseiflexus spp. have been well characterized in Mushroom Spring, where they occur with unicellular cyanobacteria related to Synechococcus spp. strains A and B'. Metatranscriptomic sequencing was applied to the microbial community to determine how FAPs regulate their gene expression in response to fluctuating environmental conditions and resource availability over a diel period. Transcripts for genes involved in the biosynthesis of bacteriochlorophylls (BChls) and photosynthetic reaction centers were much more abundant at night. Both Roseiflexus spp. and Chloroflexus spp. expressed key genes involved in the 3-hydroxypropionate (3-OHP) carbon dioxide fixation bi-cycle during the day, when these FAPs have been thought to perform primarily photoheterotrophic and/or aerobic chemoorganotrophic metabolism. The expression of genes for the synthesis and degradation of storage polymers, including glycogen, polyhydroxyalkanoates and wax esters, suggests that FAPs produce and utilize these compounds at different times during the diel cycle. We summarize these results in a proposed conceptual model for temporal changes in central carbon metabolism and energy production of FAPs living in a natural environment. The model proposes that, at night, Chloroflexus spp. and Roseiflexus spp. synthesize BChl, components of the photosynthetic apparatus, polyhydroxyalkanoates and wax esters in concert with fermentation of glycogen. It further proposes that, in daytime, polyhydroxyalkanoates and wax esters are degraded and used as carbon and electron reserves to support photomixotrophy via the 3-OHP bi-cycle.
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Affiliation(s)
- Christian G Klatt
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgra¨nd, Umea°, Va¨sterbotten SE-90183, Sweden.
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18
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Comparative and Functional Genomics of Anoxygenic Green Bacteria from the Taxa Chlorobi, Chloroflexi, and Acidobacteria. FUNCTIONAL GENOMICS AND EVOLUTION OF PHOTOSYNTHETIC SYSTEMS 2012. [DOI: 10.1007/978-94-007-1533-2_3] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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19
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Multiple types of 8-vinyl reductases for (bacterio)chlorophyll biosynthesis occur in many green sulfur bacteria. J Bacteriol 2011; 193:4996-8. [PMID: 21764919 DOI: 10.1128/jb.05520-11] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two 8-vinyl reductases, BciA and BciB, have been identified in chlorophototrophs. The bciA gene of Chlorobaculum tepidum was replaced with genes similar to bciB from other green sulfur bacteria. Pigment analyses of the complemented strains showed that the bciB homologs encode 8-vinyl reductases similar to those of cyanobacteria.
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20
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Ikeda T, Yamamoto M, Arai H, Ohmori D, Ishii M, Igarashi Y. Enzymatic and electron paramagnetic resonance studies of anabolic pyruvate synthesis by pyruvate: ferredoxin oxidoreductase from Hydrogenobacter thermophilus. FEBS J 2009; 277:501-10. [PMID: 20015072 DOI: 10.1111/j.1742-4658.2009.07506.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pyruvate: ferredoxin oxidoreductase (POR; EC 1.2.7.1) catalyzes the thiamine pyrophosphate-dependent oxidative decarboxylation of pyruvate to form acetyl-CoA and CO(2). The thermophilic, obligate chemolithoautotrophic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus TK-6, assimilates CO(2) via the reductive tricarboxylic acid cycle. In this cycle, POR acts as pyruvate synthase catalyzing the reverse reaction (i.e. reductive carboxylation of acetyl-CoA) to form pyruvate. The pyruvate synthesis reaction catalyzed by POR is an energetically unfavorable reaction and requires a strong reductant. Moreover, the reducing equivalents must be supplied via its physiological electron mediator, a small iron-sulfur protein ferredoxin. Therefore, the reaction is difficult to demonstrate in vitro and the reaction mechanism has been poorly understood. In the present study, we coupled the decarboxylation of 2-oxoglutarate catalyzed by 2-oxoglutarate: ferredoxin oxidoreductase (EC 1.2.7.3), which generates sufficiently low-potential electrons to reduce ferredoxin, to drive the energy-demanding pyruvate synthesis by POR. We demonstrate that H. thermophilus POR catalyzes pyruvate synthesis from acetyl-CoA and CO(2), confirming the operation of the reductive tricarboxylic acid cycle in this bacterium. We also measured the electron paramagnetic resonance spectra of the POR intermediates in both the forward and reverse reactions, and demonstrate the intermediacy of a 2-(1-hydroxyethyl)- or 2-(1-hydroxyethylidene)-thiamine pyrophosphate radical in both reactions. The reaction mechanism of the reductive carboxylation of acetyl-CoA is also discussed.
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Affiliation(s)
- Takeshi Ikeda
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan
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21
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Li H, Jubelirer S, Garcia Costas AM, Frigaard NU, Bryant DA. Multiple antioxidant proteins protect Chlorobaculum tepidum against oxygen and reactive oxygen species. Arch Microbiol 2009; 191:853-67. [PMID: 19784828 DOI: 10.1007/s00203-009-0514-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 08/31/2009] [Accepted: 09/14/2009] [Indexed: 11/25/2022]
Abstract
The genome of the green sulfur bacterium Chlorobaculum (Cba.) tepidum, a strictly anaerobic photolithoautotroph, is predicted to encode more than ten genes whose products are potentially involved in protection from reactive oxygen species and an oxidative stress response. The encoded proteins include cytochrome bd quinol oxidase, NADH oxidase, rubredoxin oxygen oxidoreductase, several thiol peroxidases, alkyl hydroperoxide reductase, superoxide dismutase, methionine sulfoxide reductase, and rubrerythrin. To test the physiological functions of some of these proteins, ten genes were insertionally inactivated. Wild-type Cba. tepidum cells were very sensitive to oxygen in the light but were remarkably resistant to oxygen in the dark. When wild-type and mutant cells were subjected to air for various times under dark or light condition, significant decreases in viability were detected in most of the mutants relative to wild type. Treatments with hydrogen peroxide (H(2)O(2)), tert-butyl hydroperoxide (t-BOOH) and methyl viologen resulted in more severe effects in most of the mutants than in the wild type. The results demonstrated that these putative antioxidant proteins combine to form an effective defense against oxygen and reactive oxygen species. Reverse-transcriptase polymerase chain reaction studies showed that the genes with functions in oxidative stress protection were constitutively transcribed under anoxic growth conditions.
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Affiliation(s)
- Hui Li
- Department of Biochemistry and Molecular Biology and Center for Biomolecular Structure and Function, The Pennsylvania State University , S-235 Frear Building, University Park, PA 16802, USA
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22
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Azai C, Tsukatani Y, Harada J, Oh-oka H. Sulfur oxidation in mutants of the photosynthetic green sulfur bacterium Chlorobium tepidum devoid of cytochrome c-554 and SoxB. PHOTOSYNTHESIS RESEARCH 2009; 100:57-65. [PMID: 19421892 DOI: 10.1007/s11120-009-9426-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Accepted: 04/15/2009] [Indexed: 05/27/2023]
Abstract
A mutant devoid of cytochrome c-554 (CT0075) in Chlorobium tepidum (syn. Chlorobaculum tepidum) exhibited a decreased growth rate but normal growth yield when compared to the wild type. From quantitative determinations of sulfur compounds in media, the mutant was found to oxidize thiosulfate more slowly than the wild type but completely to sulfate as the wild type. This indicates that cytochrome c-554 would increase the rate of thiosulfate oxidation by serving as an efficient electron carrier but is not indispensable for thiosulfate oxidation itself. On the other hand, mutants in which a portion of the soxB gene (CT1021) was replaced with the aacC1 cassette did not grow at all in a medium containing only thiosulfate as an electron source. They exhibited partial growth yields in media containing only sulfide when compared to the wild type. This indicates that SoxB is not only essential for thiosulfate oxidation but also responsible for sulfide oxidation. An alternative electron carrier or electron transfer path would thus be operating between the Sox system and the reaction center in the mutant devoid of cytochrome c-554. Cytochrome c-554 might function in any other pathway(s) as well as the thiosulfate oxidation one, since even green sulfur bacteria that cannot oxidize thiosulfate contain a cycA gene encoding this electron carrier.
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Affiliation(s)
- Chihiro Azai
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
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23
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Ikeda T, Ochiai T, Morita S, Nishiyama A, Yamada E, Arai H, Ishii M, Igarashi Y. Anabolic five subunit-type pyruvate:ferredoxin oxidoreductase from Hydrogenobacter thermophilus TK-6. Biochem Biophys Res Commun 2006; 340:76-82. [PMID: 16343420 DOI: 10.1016/j.bbrc.2005.11.155] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Accepted: 11/30/2005] [Indexed: 10/25/2022]
Abstract
The thermophilic, obligately chemolithoautotrophic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus TK-6, assimilates carbon dioxide via the reductive tricarboxylic acid cycle. A gene cluster, porEDABG, encoding pyruvate:ferredoxin oxidoreductase (POR), which plays a key role in this cycle, was cloned and sequenced. The nucleotide sequence and the gene organization were similar to those of the five subunit-type 2-oxoglutarate:ferredoxin oxidoreductase from this strain, although the anabolic POR had been previously reported to consist of four subunits. A small protein (8 kDa) encoded by porE, which had not been detected in the previous work, was identified in the purified recombinant POR expressed in Escherichia coli, indicating that the enzyme is also a five-subunit type. Incorporation of PorE in the wild-type POR enzyme was confirmed by immunological analysis. PorA, PorB, PorG, and PorE were similar to the alpha, beta, gamma, and delta subunits of the four subunit-type 2-oxoacid oxidoreductases, respectively, and had conserved specific motifs. PorD had no specific motifs but was essential for the expression of the active enzyme.
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Affiliation(s)
- Takeshi Ikeda
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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24
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Lin WC, Yang YL, Whitman WB. The anabolic pyruvate oxidoreductase from Methanococcus maripaludis. Arch Microbiol 2003; 179:444-56. [PMID: 12743680 DOI: 10.1007/s00203-003-0554-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2003] [Revised: 04/16/2003] [Accepted: 04/17/2003] [Indexed: 11/25/2022]
Abstract
In autotrophic methanogens, pyruvate oxidoreductase (POR) plays a key role in the assimilation of CO(2) and the biosynthesis of organic carbon. This enzyme has been purified to homogeneity, and the genes from Methanococcus maripaludis were sequenced. The purified POR contained five polypeptides with molecular masses of 47, 33, 25, 21.5 and 13 kDa. The N-terminal sequences of four of the polypeptides had high similarity to the subunits commonly associated with this enzyme from other archaea. However, the 21.5-kDa polypeptide had not been previously observed in PORs. Nucleotide sequencing of the gene cluster encoding the POR revealed six open reading frames ( porABCDEF). The genes porABCD corresponded to the subunits previously identified in PORs. On the basis of the N-terminal amino acid sequence, porE encoded the 21.5-kDa polypeptide and contained a high cysteinyl residue content and a motif indicative of a [Fe-S] cluster. porF also had a high sequence similarity to porE, a high cysteinyl residue content, and two [Fe-S] cluster motifs. Homologs to porE were also present in the genomic sequences of the autotrophic methanogens Methanocaldococcus jannaschii and Methanothermobacter thermautotrophicus. Based upon these results, it is proposed that PorE and PorF are components of a specialized system required to transfer low-potential electrons for pyruvate biosynthesis. Some biochemical properties of the purified methanococcal POR were also determined. This unstable enzyme was very sensitive to O(2 )and demonstrated high activity with pyruvate, oxaloacetate, and alpha-ketobutyrate. Methyl viologen, rubredoxin, FMN, and FAD were readily reduced. Activity was also observed with spinach and clostridial ferredoxins and cytochrome c. Coenzyme F(420) was not an electron acceptor for the purified enzyme.
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Affiliation(s)
- Winston C Lin
- Department of Microbiology, University of Georgia, Athens, GA 30602-2605, USA
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