title: Ferredoxin requirement for electron transport from the carbon monoxide dehydrogenase complex to a membrane-bound hydrogenase in acetate-grown Methanosarcina thermophila.
abstract: Cell extracts from acetate-grown Methanosarcina thermophila contained CO-oxidizing:H2-evolving activity 16-fold greater than extracts from methanol-grown cells. Following fractionation of cell extracts into soluble and membrane components, CO-dependent H2 evolution and CO-dependent methyl-coenzyme M methylreductase activities were only present in the soluble fraction, but addition of the membrane fraction enhanced both activities. A b-type cytochrome(s), present in the membrane fraction, was linked to a membrane-bound hydrogenase. CO-oxidizing:H2-evolving activity was reconstituted with: (i) CO dehydrogenase complex, (ii) a ferredoxin, and (iii) purified membranes with associated hydrogenase. The ferredoxin was a direct electron acceptor for the CO dehydrogenase complex. The ferredoxin also coupled CO oxidation by CO dehydrogenase complex to metronidazole reduction.
authors.affiliation: Department of Anaerobic Microbiology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
authors.forename: K C
authors.initials: KC
authors.lastname: Terlesky
authors.forename: J G
authors.initials: JG
authors.lastname: Ferry
mesh_terms: D000085:Acetates / Q000378:metabolism*; D019342:Acetic Acid; D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D004579:Electron Transport; D019605:Euryarchaeota / Q000201:enzymology*; D005288:Ferredoxins / Q000378:metabolism*; D006864:Hydrogenase / Q000378:metabolism*; D008795:Metronidazole / Q000378:metabolism; D009097:Multienzyme Complexes
chemical_list: D000085:Acetates; D005288:Ferredoxins; D009097:Multienzyme Complexes; D008795:Metronidazole; D006864:Hydrogenase; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase; D019342:Acetic Acid