IUBMB Enzyme Nomenclature


Accepted name: trimethylamine—corrinoid protein Co-methyltransferase

Reaction: trimethylamine + a [Co(I) trimethylamine-specific corrinoid protein] = a [methyl-Co(III) trimethylamine-specific corrinoid protein] + dimethylamine

Other name(s): mttB (gene name); trimethylamine methyltransferase

Systematic name: trimethylamine:5-hydroxybenzimidazolylcobamide Co-methyltransferase

Comments: The enzyme, which catalyses the transfer of a methyl group from trimethylamine to a trimethylamine-specific corrinoid protein (MttC), is involved in methanogenesis from trimethylamine. The enzyme contains the unusual amino acid pyrrolysine [2]. Methylation of the corrinoid protein requires the central cobalt to be in the Co(I) state. During methylation the cobalt is oxidized to the Co(III) state. The methylated corrinoid protein is substrate for EC, methylated methylamine-specific corrinoid protein:coenzyme M methyltransferase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Ferguson, D.J., Jr. and Krzycki, J.A. Reconstitution of trimethylamine-dependent coenzyme M methylation with the trimethylamine corrinoid protein and the isozymes of methyltransferase II from Methanosarcina barkeri. J. Bacteriol. 179 (1997) 846-852. [PMID: 9006042]

2. Krzycki, J.A. Function of genetically encoded pyrrolysine in corrinoid-dependent methylamine methyltransferases. Curr. Opin. Chem. Biol. 8 (2004) 484-491. [PMID: 15450490]

[EC created 2012]

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