title: Identification of methyl coenzyme M as an intermediate in methanogenesis from acetate in Methanosarcina spp.
abstract: The transfer of the methyl group of acetate to coenzyme M (2-mercaptoethanesulfonic acid; HS-CoM) during the metabolism of acetate to methane was investigated in cultures of Methanosarcina strain TM-1. The organism metabolized CD3COO- to 83% CD3H and 17% CD2H2 and produced no CDH3 or CH4. The isotopic composition of coenzyme M in cells grown on CD3COO- was analyzed with a novel gas chromatography-mass spectrometry technique. The cells contained CD3-D-CoM and CD2H-S-CoM) in a proportion similar to that of CD3H to CD2H2. These results, in conjunction with a report (J.K. Nelson and J.G. Ferry, J. Bacteriol. 160:526-532, 1984) that extracts of acetate-grown strain TM-1 contain high levels of CH3-S-CoM methylreductase, indicate that CH3-S-CoM is an intermediate in the metabolism of acetate to methane in this organism.
mesh_terms: D000085:Acetates / Q000378:metabolism*; D003903:Deuterium; D019605:Euryarchaeota / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D008623:Mercaptoethanol / Q000031:analogs & derivatives*; D015080:Mesna / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism; D008697:Methane / Q000378:metabolism; D008745:Methylation
chemical_list: D000085:Acetates; C023349:methyl coenzyme M; D008623:Mercaptoethanol; D003903:Deuterium; D015080:Mesna; D008697:Methane