title: The formylmethanofuran dehydrogenase isoenzymes in Methanobacterium wolfei and Methanobacterium thermoautotrophicum: induction of the molybdenum isoenzyme by molybdate and constitutive synthesis of the tungsten isoenzyme.
abstract: Formylmethanofuran dehydrogenase catalyzes the first step in methane formation from CO2 in methanogenic archaea. Methanobacterium wolfei and Methanobacterium thermoautotrophicum have been shown to contain two isoenzymes, a tungsten-containing isoenzyme (Fwd) and a molybdenum-containing isoenzyme (Fmd). We report here that in both thermophilic organisms the encoding genes are organized in a highly conserved fwdHFGDACB tungsten operon and in an fmdECB molybdenum operon. In both organisms, the tungsten isoenzyme was found to be constitutively transcribed, whereas the transcription of the molybdenum operon was induced by molybdate. Induction by molybdate was not significantly affected by tungstate.
authors.affiliation: Max-Planck-Institut für terrestrische Mikrobiologie, Fachbereich Biologie, Philipps-Universität, Marburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Hochheimer
authors.forename: R
authors.initials: R
authors.lastname: Hedderich
authors.forename: R K
authors.initials: RK
authors.lastname: Thauer
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D019843:Archaeal Proteins; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004790:Enzyme Induction; D019766:Genes, Archaeal; D005809:Genes, Regulator; D017014:Methanobacterium / Q000201:enzymology* / Q000235:genetics; D008982:Molybdenum / Q000378:metabolism*; D016366:Open Reading Frames
chemical_list: D019843:Archaeal Proteins; C044659:molybdate; D008982:Molybdenum; D000445:Aldehyde Oxidoreductases; C060639:formylmethanofuran dehydrogenase; C102574:formylmethanofuran dehydrogenase, tungsten, Methanobacterium thermoautotrophicus