Sarcosine/dimethylglycine N-methyltransferase

Sarcosine/dimethylglycine N-methyltransferase (, ApDMT, sarcosine-dimethylglycine methyltransferase, SDMT, sarcosine dimethylglycine N-methyltransferase, S-adenosyl-L-methionine:N,N-dimethylglycine N-methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:sarcosine(or N,N-dimethylglycine) N-methyltransferase (N,N-dimethylglycine(or betaine)-forming). This enzyme catalyses the following chemical reaction


 * 2 S-adenosyl-L-methionine + sarcosine $$\rightleftharpoons$$ 2 S-adenosyl-L-homocysteine + betaine (overall reaction)
 * (1a) S-adenosyl-L-methionine + sarcosine $$\rightleftharpoons$$ S-adenosyl-L-homocysteine + N,N-dimethylglycine
 * (1b) S-adenosyl-L-methionine + N,N-dimethylglycine $$\rightleftharpoons$$ S-adenosyl-L-homocysteine + betaine

This enzyme participates in biosynthesis of betaine from glycine in cyanobacterium Aphanocthece halophytica.