Reaction: glycine betaine + a [Co(I) glycine betaine-specific corrinoid protein] = N,N-dimethylglycine + a [methyl-Co(III) glycine betaine-specific corrinoid protein]
Other name(s): mtgB (gene name); glycine betaine methyltransferase
Systematic name: glycine betaine:[Co(I) glycine betaine-specific corrinoid protein] Co-methyltransferase
Comments: The enzyme, which catalyses the transfer of a methyl group from glycine betaine to a glycine betaine-specific corrinoid protein (MtgC), is involved in methanogenesis from glycine betaine in some methanogenic archaea, and in glycine betaine degradation in some bacteria. Unlike similar enzymes involved in methanogenesis from methylated C1 compounds, this enzyme does not contain the unusual amino acid L-pyrrolysine.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Ticak, T., Kountz, D.J., Girosky, K.E., Krzycki, J.A. and Ferguson, D.J., Jr. A nonpyrrolysine member of the widely distributed trimethylamine methyltransferase family is a glycine betaine methyltransferase. Proc. Natl. Acad. Sci. USA 111 (2014) E4668-E4676. [PMID: 25313086]
2. Creighbaum, A.J., Ticak, T., Shinde, S., Wang, X. and Ferguson, D.J., Jr. Examination of the glycine betaine-dependent methylotrophic methanogenesis pathway: insights into anaerobic quaternary amine methylotrophy. Front. Microbiol. 10 (2019) 2572. [PMID: 31787957]