Reaction: S-adenosyl-L-methionine + glycine = S-adenosyl-L-homocysteine + sarcosine
Glossary: sarcosine = N-methylglycine
Other name(s): glycine methyltransferase; S-adenosyl-L-methionine:glycine methyltransferase; GNMT
Systematic name: S-adenosyl-L-methionine:glycine N-methyltransferase
Comments: This enzyme is thought to play an important role in the regulation of methyl group metabolism in the liver and pancreas by regulating the ratio between S-adenosyl-L-methionine and S-adenosyl-L-homocysteine. It is inhibited by 5-methyltetrahydrofolate pentaglutamate [4]. Sarcosine, which has no physiological role, is converted back into glycine by the action of EC 1.5.8.3, sarcosine dehydrogenase.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37228-72-1
References:
1. Blumenstein, J. and Williams, G.R. Glycine methyltransferase. Can. J. Biochem. Physiol. 41 (1963) 201-210. [PMID: 13971907]
2. Ogawa, H., Gomi, T., Takusagawa, F. and Fujioka, M. Structure, function and physiological role of glycine N-methyltransferase. Int. J. Biochem. Cell Biol. 30 (1998) 13-26. [PMID: 9597750]
3. Yeo, E.J., Briggs, W.T. and Wagner, C. Inhibition of glycine N-methyltransferase by 5-methyltetrahydrofolate pentaglutamate. J. Biol. Chem. 274 (1999) 37559-37564. [PMID: 10608809]
4. Martinov, M.V., Vitvitsky, V.M., Mosharov, E.V., Banerjee, R. and Ataullakhanov, F.I. A substrate switch: a new mode of regulation in the methionine metabolic pathway. J. Theor. Biol. 204 (2000) 521-532. [PMID: 10833353]
5. Takata, Y., Huang, Y., Komoto, J., Yamada, T., Konishi, K., Ogawa, H., Gomi, T., Fujioka, M. and Takusagawa, F. Catalytic mechanism of glycine N-methyltransferase. Biochemistry 42 (2003) 8394-8402. [PMID: 12859184]
6. Pakhomova, S., Luka, Z., Grohmann, S., Wagner, C. and Newcomer, M.E. Glycine N-methyltransferases: a comparison of the crystal structures and kinetic properties of recombinant human, mouse and rat enzymes. Proteins 57 (2004) 331-337. [PMID: 15340920]