title: Incorporation of coenzyme M into component C of methylcoenzyme M methylreductase during in vitro methanogenesis.
abstract: Reduction of the methyl group of [methyl-3H,thio-35S]2-methylthioethanesulfonic acid to methane by a reconstituted enzyme system resulted in a slow incorporation of [thio-35S]2-mercaptoethanesulfonic acid (HS-CoM) into component C of the methylreductase system. Only 35S label was associated with component C. The ratio of incorporated HS-CoM to component C was 1.96 to 1. The ratio of HS-CoM to factor F430, the nickel-containing cofactor of component C, was 1.18 to 1. Extraction of factor F430 from the protein resulted in the release of 62 +/- 8% of the 35S label, but the label was not covalently bound to F430. The incorporation of label into component C was coupled to methyl group reduction; no label was found associated with component C from a reconstituted reaction containing unlabeled 2-methylthioethanesulfonic acid and [thio-35S]HS-CoM.
mesh_terms: D019605:Euryarchaeota / Q000201:enzymology*; D007700:Kinetics; D008623:Mercaptoethanol / Q000031:analogs & derivatives*; D015080:Mesna / Q000302:isolation & purification / Q000378:metabolism*; D008697:Methane / Q000378:metabolism*; D010088:Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D013462:Sulfur Radioisotopes
chemical_list: D013462:Sulfur Radioisotopes; D008623:Mercaptoethanol; D010088:Oxidoreductases; C021572:methyl coenzyme M reductase; D015080:Mesna; D008697:Methane