title: The active species of 'CO2' utilized by formylmethanofuran dehydrogenase from methanogenic Archaea.
abstract: Formylmethanofuran dehydrogenase from methanogenic Archaea catalyzes the reversible conversion of CO2 and methanofuran to formylmethanofuran, which is an intermediate in methanogenesis from CO2, a biological process yielding approximately 0.3 billion tons of CH4 per year. With the enzyme from Methanosarcina barkeri, it is shown that CO2 rather than HCO3- is the active species of 'CO2' utilized by the dehydrogenase. Evidence is also presented that the enzyme catalyzes a methanofuran-dependent exchange between CO2 and the formyl group of formylmethanofuran. The results are consistent with N-carboxymethanofuran being an intermediate in CO2 reduction to formylmethanofuran.
authors.affiliation: Max-Planck-Institut für terrestrische Mikrobiologie and Laboratorium für Mikrobiologie des Fachbereichs Biologie der Philipps-Universität, Marburg, Germany.
authors.forename: J A
authors.initials: JA
authors.lastname: Vorholt
authors.forename: R K
authors.initials: RK
authors.lastname: Thauer
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D001639:Bicarbonates / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism*; D002250:Carbon Radioisotopes; D005663:Furans / Q000378:metabolism; D007700:Kinetics; D017021:Methanosarcina barkeri / Q000201:enzymology* / Q000378:metabolism; D015394:Molecular Structure; D013696:Temperature
chemical_list: D001639:Bicarbonates; D002250:Carbon Radioisotopes; D005663:Furans; D002245:Carbon Dioxide; C044289:carbon dioxide reduction factor; C050842:formylmethanofuran; D000445:Aldehyde Oxidoreductases; C060639:formylmethanofuran dehydrogenase