IUBMB Enzyme Nomenclature


Accepted name: sarcosine/dimethylglycine N-methyltransferase

Reaction: 2 S-adenosyl-L-methionine + sarcosine = 2 S-adenosyl-L-homocysteine + betaine (overall reaction)
(1) S-adenosyl-L-methionine + sarcosine = S-adenosyl-L-homocysteine + N,N-dimethylglycine

(2) S-adenosyl-L-methionine + N,N-dimethylglycine = S-adenosyl-L-homocysteine + betaine

Glossary: sarcosine = N-methylglycine
betaine = glycine betaine = N,N,N-trimethylglycine

Other name(s): ApDMT; sarcosine-dimethylglycine methyltransferase; SDMT; sarcosine dimethylglycine N-methyltransferase; S-adenosyl-L-methionine:N,N-dimethylglycine N-methyltransferase

Systematic name: S-adenosyl-L-methionine:sarcosine(or N,N-dimethylglycine) N-methyltransferase [N,N-dimethylglycine(or betaine)-forming]

Comments: Cells of the oxygen-evolving halotolerant cyanobacterium Aphanocthece halophytica synthesize betaine from glycine by a three-step methylation process. The first enzyme, EC, glycine/sarcosine N-methyltransferase, leads to the formation of either sarcosine or N,N-dimethylglycine, which is further methylated to yield betaine (N,N,N-trimethylglycine) by the action of this enzyme. Both of these enzymes can catalyse the formation of N,N-dimethylglycine from sarcosine [3]. The reactions are strongly inhibited by S-adenosyl-L-homocysteine.

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


1. Nyyssölä, A., Kerovuo, J., Kaukinen, P., von Weymarn, N. and Reinikainen, T. Extreme halophiles synthesize betaine from glycine by methylation. J. Biol. Chem. 275 (2000) 22196-22201. [PMID: 10896953]

2. Nyyssölä, A., Reinikainen, T. and Leisola, M. Characterization of glycine sarcosine N-methyltransferase and sarcosine dimethylglycine N-methyltransferase. Appl. Environ. Microbiol. 67 (2001) 2044-2050. [PMID: 11319079]

3. Waditee, R., Tanaka, Y., Aoki, K., Hibino, T., Jikuya, H., Takano, J., Takabe, T. and Takabe, T. Isolation and functional characterization of N-methyltransferases that catalyze betaine synthesis from glycine in a halotolerant photosynthetic organism Aphanothece halophytica. J. Biol. Chem. 278 (2003) 4932-4942. [PMID: 12466265]

[EC created 2005]

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