glycine/sarcosine N-methyltransferase;
ApGSMT;
glycine-sarcosine methyltransferase;
GSMT;
GMT;
glycine sarcosine N-methyltransferase;
S-adenosyl-L-methionine:sarcosine N-methyltransferase

Transferases;
Transferring one-carbon groups;
Methyltransferases

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

2 S-adenosyl-L-methionine + glycine = 2 S-adenosyl-L-homocysteine + N,N-dimethylglycine (overall reaction) [RN:R10060];
(1a) S-adenosyl-L-methionine + glycine = S-adenosyl-L-homocysteine + sarcosine [RN:R00367];
(1b) S-adenosyl-L-methionine + sarcosine = S-adenosyl-L-homocysteine + N,N-dimethylglycine [RN:R07243]

R00367 R07243 R10060

S-adenosyl-L-methionine [CPD:C00019];
glycine [CPD:C00037];
sarcosine [CPD:C00213]

Cells of the oxygen-evolving halotolerant cyanobacterium Aphanocthece halophytica synthesize betaine from glycine by a three-step methylation process. This is the first enzyme and it 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 EC 2.1.1.157, sarcosine/dimethylglycine N-methyltransferase. Differs from EC 2.1.1.20, glycine N-methyltransferase, as it can further methylate the product of the first reaction. Acetate, dimethylglycine and S-adenosyl-L-homocysteine can inhibit the reaction [3].

1  [PMID:10896953]

Nyyssola A, Kerovuo J, Kaukinen P, von Weymarn N, Reinikainen T.

Extreme halophiles synthesize betaine from glycine by methylation.

J. Biol. Chem. 275 (2000) 22196-201.

Actinopolyspora halophila, Ectothiorhodospira halochloris

2  [PMID:11319079]

Nyyssola A, Reinikainen T, Leisola M.

Characterization of glycine sarcosine N-methyltransferase and sarcosine dimethylglycine N-methyltransferase.

Appl. Environ. Microbiol. 67 (2001) 2044-50.

Ectothiorhodospira halochloris

3  [PMID:12466265]

Waditee R, Tanaka Y, Aoki K, Hibino T, Jikuya H, Takano J, Takabe T, 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) 4932-42.

Actinopolyspora halophila