Homocysteine S-methyltransferase

homocysteine S-methyltransferase
Identifiers
EC number	2.1.1.10
CAS number	9012-40-2
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles

In enzymology, a homocysteine S-methyltransferase (EC 2.1.1.10) 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.

References

• Balish E, Shapiro SK (1967). "Methionine biosynthesis in Escherichia coli: induction and repression of methylmethionine(or adenosylmethionine):homocysteine methyltransferase". Arch. Biochem. Biophys. 119 (1): 62–8. doi:10.1016/0003-9861(67)90429-8. PMID 4861151. 
• Shapiro SK (1958). "Adenosylmethionine-homocysteine transmethylase". Biochim. Biophys. Acta 29 (2): 405–409. doi:10.1016/0006-3002(58)90199-9. PMID 13572358. 
• Shapiro SK and Yphantis DA (1959). "Assay of S-methylmethionine and S-adenosylmethionine homocysteine transmethylases". Biochim. Biophys. Acta 36: 241–244. doi:10.1016/0006-3002(59)90089-7. PMID 14445542.