IUBMB Enzyme Nomenclature


Accepted name: methylamine—corrinoid protein Co-methyltransferase

Reaction: methylamine + a [Co(I) methylamine-specific corrinoid protein] = a [methyl-Co(III) methylamine-specific corrinoid protein] + NH3

Other name(s): mtmB (gene name); monomethylamine methyltransferase

Systematic name: monomethylamine:5-hydroxybenzimidazolylcobamide Co-methyltransferase

Comments: The enzyme, which catalyses the transfer of a methyl group from methylamine to a methylamine-specific corrinoid protein (MtmC), is involved in methanogenesis from methylamine. The enzyme contains the unusual amino acid pyrrolysine [3]. 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, PDB, CAS registry number:


1. Burke, S.A. and Krzycki, J.A. Reconstitution of Monomethylamine:Coenzyme M methyl transfer with a corrinoid protein and two methyltransferases purified from Methanosarcina barkeri. J. Biol. Chem. 272 (1997) 16570-16577. [PMID: 9195968]

2. Burke, S.A., Lo, S.L. and Krzycki, J.A. Clustered genes encoding the methyltransferases of methanogenesis from monomethylamine. J. Bacteriol. 180 (1998) 3432-3440. [PMID: 9642198]

3. 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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