IUBMB Enzyme Nomenclature


Accepted name: methanol—corrinoid protein Co-methyltransferase

Reaction: methanol + a [Co(I) methanol-specific corrinoid protein] = a [methyl-Co(III) methanol-specific corrinoid protein] + H2O

Other name(s): methanol cobalamin methyltransferase; methanol:5-hydroxybenzimidazolylcobamide methyltransferase; MT 1 (ambiguous); methanol—5-hydroxybenzimidazolylcobamide Co-methyltransferase; mtaB (gene name)

Systematic name: methanol:5-hydroxybenzimidazolylcobamide Co-methyltransferase

Comments: The enzyme, which catalyses the transfer of methyl groups from methanol to a methanol-specific corrinoid protein (MtaC), is involved in methanogenesis from methanol. 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. Free cob(I)alamin can substitute for the corrinoid protein in vitro [2]. Inactivated by oxygen and other oxidizing agents, and reactivated by catalytic amounts of ATP and hydrogen.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 86611-98-5


1. van der Meijden, P., te Brömmelstroet, B.W., Poirot, C.M., van der Drift, C. and Vogels, G.D. Purification and properties of methanol:5-hydroxybenzimidazolylcobamide methyltransferase from Methanosarcina barkeri. J. Bacteriol. 160 (1984) 629-635. [PMID: 6438059]

2. Sauer, K. and Thauer, R.K. Methanol:coenzyme M methyltransferase from Methanosarcina barkeri – substitution of the corrinoid harbouring subunit MtaC by free cob(I)alamin. Eur. J. Biochem. 261 (1999) 674-681. [PMID: 10215883]

[EC created 1989, modified 2012]

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