Glycine/sarcosine/dimethylglycine N-methyltransferase explained

Glycine/sarcosine/dimethylglycine N-methyltransferase
Ec Number:	2.1.1.162

Glycine/sarcosine/dimethylglycine N-methyltransferase (GSDMT, glycine sarcosine dimethylglycine N-methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:glycine(or sarcosine or N,N-dimethylglycine) N-methyltransferase (sarcosine(or N,N-dimethylglycine or betaine)-forming).^[1] This enzyme catalyses the following chemical reaction

\rightleftharpoons 3 S-adenosyl-L-homocysteine + betaine (overall reaction)

(1a) S-adenosyl-L-methionine + glycine

\rightleftharpoons S-adenosyl-L-homocysteine + sarcosine

(1b) S-adenosyl-L-methionine + sarcosine

\rightleftharpoons S-adenosyl-L-homocysteine + N,N-dimethylglycine

(1c) S-adenosyl-L-methionine + N,N-dimethylglycine

\rightleftharpoons S-adenosyl-L-homocysteine + betaine

This enzyme from the halophilic methanoarchaeon Methanohalophilus portucalensis can methylate glycine and all of its intermediates to form the compatible solute trimethylglycine.

Notes and References

1. Lai MC, Wang CC, Chuang MJ, Wu YC, Lee YC . Effects of substrate and potassium on the betaine-synthesizing enzyme glycine sarcosine dimethylglycine N-methyltransferase from a halophilic methanoarchaeon Methanohalophilus portucalensis . Research in Microbiology . 157 . 10 . 948–55 . December 2006 . 17098399 . 10.1016/j.resmic.2006.08.007 . free .