Homocysteine S-methyltransferase

In enzymology, a homocysteine S-methyltransferase is an enzyme that catalyzes the chemical reaction


 * S-adenosyl-L-methionine + L-homocysteine $$\rightleftharpoons$$ S-adenosyl-L-homocysteine + L-methionine

Thus, the two substrates of this enzyme are S-adenosyl methionine and L-homocysteine, whereas its two products are S-adenosylhomocysteine and L-methionine.

This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:L-homocysteine S-methyltransferase. Other names in common use include S-adenosylmethionine homocysteine transmethylase, S-methylmethionine homocysteine transmethylase, adenosylmethionine transmethylase, methylmethionine:homocysteine methyltransferase, adenosylmethionine:homocysteine methyltransferase, homocysteine methylase, homocysteine methyltransferase, homocysteine transmethylase, L-homocysteine S-methyltransferase, S-adenosyl-L-methionine:L-homocysteine methyltransferase, S-adenosylmethionine-homocysteine transmethylase, and S-adenosylmethionine:homocysteine methyltransferase. This enzyme participates in methionine metabolism.