CO-dependent H2 evolution by Rhodospirillum rubrum: Role of CODH:CooF complex

Singer, Steven W.; Hirst, Marissa B.; Ludden, Paul W.

doi:10.1016/j.bbabio.2006.10.003

Cited by 54 publications

(48 citation statements)

References 42 publications

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“…gelatinosus chromatophore membranes following CO treatment (data not shown). The Western blotting data on the wild-type strain are therefore in agreement with and complement the studies of R. rubrum showing that the hydrogenase genes are transcriptionally induced by CO (12), with a concomitant accumulation of the CooH protein (34). The Western blots confirmed the absence of CooH in GV1762 following a 4-h CO treatment and its restoration in GV1762c.…”

Section: Vol 76 2010 Characterization Of Genes In Rubrivivax Gelatisupporting

confidence: 77%

Characterization of Genes Responsible for the CO-Linked Hydrogen Production Pathway in Rubrivivax gelatinosus

Vanzin

Smolinski

et al. 2010

Appl Environ Microbiol

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Upon exposure to carbon monoxide, the purple nonsulfur photosynthetic bacterium Rubrivivax gelatinosus produces hydrogen concomitantly with the oxidation of CO according to the equation CO ؉ H 2 O 7 CO 2 ؉ H 2 . Yet little is known about the genetic elements encoding this reaction in this organism. In the present study, we use transposon mutagenesis and functional complementation to uncover three clustered genes, cooL, cooX, and cooH, in Rubrivivax gelatinosus putatively encoding part of a membrane-bound, multisubunit NiFe-hydrogenase. We present the complete amino acid sequences for the large catalytic subunit and its electron-relaying small subunit, encoded by cooH and cooL, respectively. Sequence alignment reveals a conserved region in the large subunit coordinating a binuclear [NiFe] center and a conserved region in the small subunit coordinating a [4Fe-4S] cluster. Protein purification experiments show that a protein fraction of 58 kDa molecular mass could function in H 2 evolution mediated by reduced methyl viologen. Western blotting experiments show that the two hydrogenase subunits are detectable and accumulate only when cells are exposed to CO. The cooX gene encodes a putative Fe-S protein mediating electron transfer to the hydrogenase small subunit. We conclude that these three Rubrivivax proteins encompass part of a membrane-bound, multisubunit NiFe-hydrogenase belonging to the energy-converting hydrogenase (Ech) type, which has been found among diverse microbes with a common feature in coupling H 2 production with proton pumping for energy generation.Hydrogen is a clean fuel, and if produced from renewable resources, it has the potential to address both energy security and environmental concerns (14). One such renewable feedstock is waste biomass, which can be gasified to generate CO (along with H 2 ) as an energy-enriched substrate. Numerous anaerobic microbes have been reported to carry out a CO oxidation reaction leading to H 2 production according to the equation CO ϩ H 2 O 7 CO 2 ϩ H 2 (5,6,17,26,37,38,39). More in-depth understanding of the underlying metabolic pathways along with the genes and enzymes involved thereby has immense potential in developing a feasible approach for renewable H 2 production from biomass-derived CO. Carbon monoxide oxidation is catalyzed initially by the enzyme CO dehydrogenase (CODH), and the resulting reducing equivalents are shuttled via a series of iron-sulfur proteins to a terminal hydrogenase, yielding H 2 as the end product. The CO oxidation reaction also yields energy, as evidenced by the COsupported ATP generation and cell growth in the purple nonsulfur photosynthetic bacteria Rubrivivax gelatinosus (Rx. gelatinosus) and Rhodospirillum rubrum and in Methanosarcina barkeri, with the former two microbes capable of using CO as the sole carbon substrate in darkness (7,8,20,25,38). Biological CO oxidation thereby plays a significant role not only in the generation of H 2 from CO (and H 2 O) but also in yielding ATP, although the mechanism of the latter is unknown...

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Section: Vol 76 2010 Characterization Of Genes In Rubrivivax Gelatisupporting

confidence: 77%

Characterization of Genes Responsible for the CO-Linked Hydrogen Production Pathway in Rubrivivax gelatinosus

Vanzin

Smolinski

et al. 2010

Appl Environ Microbiol

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“…Interestingly, it seems to be a component of the CO-oxidizing system, since it is coupled to the carbon monoxide dehydrogenase gene (CODH). A similar COoxidation/H 2 -evolution enzyme complex, associated with [NiFe] hydrogenase, was found in the membrane of Rhodospirillum rubrum and has been described as allowing the bacterium to metabolize carbon monoxide in the reaction CO+H 2 O A CO 2 +H 2 (Singer et al, 2006). Neither hydrogenase nor the CODH subunit are predicted membrane proteins in C. bolteae, therefore a function as a putative energy coupling site is hypothetical.…”

Section: The Monomeric [Fefe] Hydrogenases Of Group Amentioning

confidence: 95%

“…In nitrogen-fixing bacteria, e.g. Azotobacter chroococcum, [NiFe] hydrogenase is induced when hydrogen is produced as an intrinsic part of nitrogenase (Yates et al, 1997 A small group of multisubunit membrane-associated [NiFe] hydrogenases, closely related to proton-pumping NADH : ubiquinone oxidoreductase (complex I), has been identified in several organisms including Escherichia coli (hydrogenases 3 and 4; Maeda et al, 2007;Self et al, 2004), Rhodospirillum rubrum (Singer et al, 2006), Methanosarcina barkeri (Kurkin et al, 2002) and Desulfovibrio gigas (Rodrigues et al, 2003). These have been assigned to group 4 described by Vignais et al (2001), which is characterized by membrane-associated H 2 -evolving respiratory [NiFe] hydrogenases.…”

Section: Hydrogenasesmentioning

confidence: 99%

The surprising diversity of clostridial hydrogenases: a comparative genomic perspective

et al. 2010

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Among the large variety of micro-organisms capable of fermentative hydrogen production, strict anaerobes such as members of the genus Clostridium are the most widely studied. They can produce hydrogen by a reversible reduction of protons accumulated during fermentation to dihydrogen, a reaction which is catalysed by hydrogenases. Sequenced genomes provide completely new insights into the diversity of clostridial hydrogenases. Building on previous reports, we found that [FeFe] hydrogenases are not a homogeneous group of enzymes, but exist in multiple forms with different modular structures and are especially abundant in members of the genus Clostridium. This unusual diversity seems to support the central role of hydrogenases in cell metabolism. In particular, the presence of multiple putative operons encoding multisubunit [FeFe] hydrogenases highlights the fact that hydrogen metabolism is very complex in this genus. In contrast with [FeFe] hydrogenases, their [NiFe] hydrogenase counterparts, widely represented in other bacteria and archaea, are found in only a few clostridial species. Surprisingly, a heteromultimeric Ech hydrogenase, known to be an energy-converting [NiFe] hydrogenase and previously described only in methanogenic archaea and some sulfur-reducing bacteria, was found to be encoded by the genomes of four cellulolytic strains: Clostridum cellulolyticum, Clostridum papyrosolvens, Clostridum thermocellum and Clostridum phytofermentans. IntroductionMolecular hydrogen is a key intermediate in the metabolic interactions of a wide range of micro-organisms. The main routes for biohydrogen production are photoproduction and dark fermentation with the latter providing higher rates of gas evolution without external energy requirements and the possibility of converting a wide range of biomassbased substrates into hydrogen. Among a large variety of micro-organisms capable of fermentative hydrogen production, strict anaerobes such as members of the genus Clostridium are the most widely studied (Levin et al., 2004). Clostridia are the dominant micro-organisms in mixed microaerophilic communities capable of hydrogen production from biomass waste treatment. They can produce hydrogen by butyric and mixed acid fermentations at optimal pH values ranging from 4.5 to 5.5 (Fang & Liu, 2002). While fermentative conditions, such as substrate type, pH, hydraulic and solid retention time, H 2 partial pressure and the concentration of acids produced, have been extensively studied and optimized (Li & Fang, 2007;Van Ginkel et al., 2005;Khanal et al., 2004), relatively little is known about the different forms of hydrogenases present in clostridia.Three classes of enzymes are capable of hydrogen production: nitrogenases (Masukawa et al., 2002), alkaline phosphatases (Yang & Metcalf, 2004) and hydrogenases (Heinekey, 2009;Meyer, 2007;Vignais & Colbeau, 2004;Vignais et al., 2001). However, owing to their highly reactive and complex metallocenters, hydrogenases are regarded as the most efficient with turnover rates 1000 times hig...

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“…Also, in CO-grown cells, the marked expression of monofunctional CODH (TON_1018), homologous to CooS and CooF (TON_1017), indicates the possibility that T. onnurineus NA1 can evolve H 2 during growth on CO, as displayed by Rhodospirillum rubrum (68) and Carboxydothermus hydrogenoformans (69,70). In addition, it has been reported that energy-converting hydrogenase-type hydrogenases couple the formation of H 2 to the generation of the proton motive force that drives ATP synthesis (66,71).…”

Section: Analysis Of One-carbon Metabolism In T Onnurineus Na1mentioning

confidence: 99%

Proteome Analyses of Hydrogen-producing Hyperthermophilic Archaeon Thermococcus onnurineus NA1 in Different One-carbon Substrate Culture Conditions

Moon

Kwon

Yun

et al. 2012

Molecular & Cellular Proteomics

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Thermococcus onnurineus NA1, a sulfur-reducing hyperthermophilic archaeon, is capable of H 2 -producing growth, considered to be hydrogenogenic carboxydotrophy. Utilization of formate as a sole energy source has been well studied in T. onnurineus NA1. However, whether formate can be used as its carbon source remains unknown. To obtain a global view of the metabolic characteristics of H 2 -producing growth, a quantitative proteome analysis of T. onnurineus NA1 grown on formate, CO, and starch was performed by combining one-dimensional SDS-PAGE with nano UPLC-MS E . A total of 587 proteins corresponding to 29.7% of the encoding genes were identified, and the major metabolic pathways (especially energy metabolism) were characterized at the protein level. Expression of glycolytic enzymes was common but more highly induced in starch-grown cells. In contrast, enzymes involved in key steps of the gluconeogenesis and pentose phosphate pathways were strongly up-regulated in formate-grown cells, suggesting that formate could be utilized as a carbon source by T. onnurineus NA1. In accordance with the genomic analysis, comprehensive proteomic analysis also revealed a number of hydrogenase clusters apparently associated with formate metabolism. On the other hand, CODH and CO-induced hydrogenases belonging to the Hyg4-II cluster, as well as sulfhydrogenase-I and Mbx, were prominently expressed during CO culture. Our data suggest that CO can be utilized as a sole energy source for H 2 production via an electron transport mechanism and that CO 2 produced from catabolism or CO oxidation by CODH and CO-induced hydrogenases may subsequently be assimilated into the organic carbon. Hyperthermophilic archaea can use a wide variety of carbon and energy sources. Hyperthermophiles are widely distributed in extreme habitats such as deep-sea thermal vents, hot springs, and deep oil reservoirs (1-3). So far, the most frequently studied hyperthermophiles are from the genera Thermococcus and Pyrococcus, which belong to the order Thermococcales (4). These are ecologically important hyperthermophilic archaea for understanding the physiology and metabolic activity of microbial consortia within marine hotwater ecosystems. Members of the order Thermococcales are anaerobic heterotrophs that utilize various complex substrates with elemental sulfur (S 0 ) or protons as electron acceptors (4 -6). Unlike other Thermococcales, Thermococcus strain AM4 (7) and Thermococcus onnurineus NA1 (8) are capable of lithotrophic carbon monoxide-dependent hydrogenogenic growth. These Thermococcus strains use CO as a carbon and energy source by converting it into carbon dioxide (CO 2 ). In addition, several hyperthermophilic archaea of the genus Thermococcus can grow with formate as an electron donor, producing hydrogen gas (9). T. onnurineus NA1 is a sulfur-reducing hyperthermophilic archaeon isolated from a deep sea hydrothermal vent area in the Eastern Manus Basin of Papua New Guinea (10). It is one of the more metabolically versatile hyperthermophiles in that it...

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CO-dependent H2 evolution by Rhodospirillum rubrum: Role of CODH:CooF complex

Cited by 54 publications

References 42 publications

Characterization of Genes Responsible for the CO-Linked Hydrogen Production Pathway in Rubrivivax gelatinosus

Characterization of Genes Responsible for the CO-Linked Hydrogen Production Pathway in Rubrivivax gelatinosus

The surprising diversity of clostridial hydrogenases: a comparative genomic perspective

Proteome Analyses of Hydrogen-producing Hyperthermophilic Archaeon Thermococcus onnurineus NA1 in Different One-carbon Substrate Culture Conditions

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