PMID:17123462

Citation	Singer, SW, Hirst, MB and Ludden, PW (2006) CO-dependent H2 evolution by Rhodospirillum rubrum: role of CODH:CooF complex. Biochim. Biophys. Acta 1757:1582-91
Abstract	Upon exposure to CO during anaerobic growth, the purple phototrophic bacterium Rhodospirillum rubrum expresses a CO-oxidizing H(2) evolving enzymatic system. The CO-oxidizing enzyme, carbon monoxide dehydrogenase (CODH), has been purified and extensively characterized. However the electron transfer pathway from CODH to the CO-induced hydrogenase that evolves H(2) is not well understood. CooF is an Fe-S protein that is the proposed mediator of electron transfer between CODH and the CO-induced hydrogenase. Here we present the spectroscopic and biochemical properties of the CODH:CooF complex. The characteristic EPR signals observed for CODH are largely insensitive to CooF complexation. Metal analysis and EPR spectroscopy show that CooF contains 2 Fe(4)S(4) clusters. The observation of 2 Fe(4)S(4) clusters for CooF contradicts the prediction of 4 Fe(4)S(4) clusters based on analysis of the amino acid sequence of CooF and structural studies of CooF homologs. Comparison of in vivo and in vitro CO-dependent H(2) evolution indicates that approximately 90% of the activity is lost upon cell lysis. We propose that the loss of two labile Fe-S clusters from CooF during cell lysis may be responsible for the low in vitro CO-dependent H(2) evolution activity. During the course of these studies, a new assay for CODH:CooF was developed using membranes from an R. rubrum mutant that did not express CODH:CooF, but expressed high levels of the CO-induced hydrogenase. The assay revealed that the CO-induced hydrogenase requires the presence of CODH:CooF for optimal H(2) evolution activity.
Links	PubMed Online version:10.1016/j.bbabio.2006.10.003
Keywords	Aldehyde Oxidoreductases/chemistry; Aldehyde Oxidoreductases/genetics; Aldehyde Oxidoreductases/metabolism; Bacterial Proteins/chemistry; Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Carbon Monoxide/metabolism; Electron Spin Resonance Spectroscopy; Genes, Bacterial; Hydrogen/metabolism; Multienzyme Complexes/chemistry; Multienzyme Complexes/genetics; Multienzyme Complexes/metabolism; Multiprotein Complexes; Protein Subunits; Regulon; Rhodospirillum rubrum/genetics; Rhodospirillum rubrum/metabolism
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
RHORU:COOF	enables	GO:0009055: electron transfer activity	ECO:0000315: mutant phenotype evidence used in manual assertion		F		Seeded From UniProt	complete
RHORU:COOF	involved_in	GO:0019645: anaerobic electron transport chain	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete
RHORU:COOF		GO:0009055: electron carrier activity	ECO:0000315:		F		Table 2	complete CACAO 3342
RHORU:COOF		GO:0019645: anaerobic electron transport chain	ECO:0000315:		P		Table 2	complete CACAO 3350

References

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