title: Carbon monoxide dehydrogenase from Methanosarcina frisia Gö1. Characterization of the enzyme and the regulated expression of two operon-like cdh gene clusters.
abstract: Carbon monoxide dehydrogenase (Cdh) has been anaerobically purified from Methanosarcina frisia Gö1. The enzyme is a Ni2+-, Fe2+-, and S2--containing alpha2beta2 heterotetramer of 214 kDa with a pI of 5.2 and subunits of 94 and 19 kDa. It has a Vmax of 0.3 mmol of CO min-1 mg-1 and Km values for CO and methyl viologen of approximately 0.9 mM and 0.12 mM, respectively. EPR spectroscopy on the reduced enzyme showed two overlapping signals: one indicative for 2 (4Fe-4S)+ clusters and a second signal that is atypical for standard Fe/S clusters. The latter was, together with high-spin EPR signals of the oxidized enzyme tentatively assigned to an Fe/S cluster of high nuclearity.
authors.affiliation: Department of Microbiology, Wageningen Agricultural University, Wageningen 6703 CT, The Netherlands.
authors.forename: R I
authors.initials: RI
authors.lastname: Eggen
authors.forename: R
authors.initials: R
authors.lastname: van Kranenburg
authors.forename: A J
authors.initials: AJ
authors.lastname: Vriesema
authors.forename: A C
authors.initials: AC
authors.lastname: Geerling
authors.forename: M F
authors.initials: MF
authors.lastname: Verhagen
authors.forename: W R
authors.initials: WR
authors.lastname: Hagen
authors.forename: W M
authors.initials: WM
authors.lastname: de Vos
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002248:Carbon Monoxide / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D007506:Iron-Sulfur Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D007700:Kinetics; D017020:Methanosarcina / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005810:Multigene Family; D009876:Operon; D010269:Paraquat; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid
chemical_list: D007506:Iron-Sulfur Proteins; D009097:Multienzyme Complexes; D002248:Carbon Monoxide; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase; D010269:Paraquat