The enzyme, present in methanogenic archaea, catalyses a modification of an L-arginine residue at the active site of EC 2.8.4.1, coenzyme-B sulfoethylthiotransferase (better known as methyl-coenzyme M reductase), which catalyses the last and methane-releasing step of methanogenesis. The enzyme is a radical AdoMet (radical SAM) enzyme and contains a [4Fe-4S] cluster and a Coalpha-[alpha-(5-hydroxybenzimidazolyl)]-cobamide cofactor. The methyl group, which is derived from S-adenosyl-L-methionine, is transferred to the cob(I)amide cofactor, forming methylcob(III)amide as an intermediate carrier, before being transferred to the arginine residue.
Methanogenesis marker protein 10 (Mmp10) from Methanosarcina acetivorans is a radical S-adenosylmethionine methylase that unexpectedly requires cobalamin.
Lyu Z, Shao N, Chou CW, Shi H, Patel R, Duin EC, Whitman WB.
Title
Posttranslational Methylation of Arginine in Methyl Coenzyme M Reductase Has a Profound Impact on both Methanogenesis and Growth of Methanococcus maripaludis.
