Betaine—homocysteine S-methyltransferase
Class of enzymes
From Wikipedia, the free encyclopedia
In enzymology, a betaine-homocysteine S-methyltransferase also known as betaine-homocysteine methyltransferase (BHMT) is a zinc metallo-enzyme that catalyzes the transfer of a methyl group from trimethylglycine and a hydrogen ion from homocysteine to produce dimethylglycine and methionine respectively:[2]
| betaine-homocysteine S-methyltransferase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Crystal structure of rat liver betaine homocysteine s-methyltransferase.[1] | |||||||||
| Identifiers | |||||||||
| EC no. | 2.1.1.5 | ||||||||
| CAS no. | 9029-78-1 | ||||||||
| 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 / QuickGO | ||||||||
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BHMT belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. It participates in the metabolism of glycine, serine, threonine, and methionine.
Isozymes
In humans, there are two isozymes, BHMT[3][4] and BHMT2,[5][6] each encoded by a separate gene.
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Tissue distribution
BHMT is expressed most predominantly in the liver and kidney.[7]
Clinical significance
Mutations in the BHMT gene are known to exist in humans. Anomalies may influence the metabolism of homocysteine, which is implicated in disorders ranging from vascular disease, autism, and schizophrenia to neural tube birth defects such as spina bifida.
