Betaine—homocysteine S-methyltransferase
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 | ||||||||
|
In the field of 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]
- Trimethylglycine (methyl donor) + homocysteine (hydrogen donor) → dimethylglycine (hydrogen receiver) + methionine (methyl receiver)
![](https://upload.wikimedia.org/wikipedia/commons/thumb/c/ca/Betaine%E2%80%94homocysteine_S-methyltransferase.png/440px-Betaine%E2%80%94homocysteine_S-methyltransferase.png)
This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. This enzyme participates in the metabolism of glycine, serine, threonine and also methionine.
Isozymes
In humans, there are two isozymes, BHMT[3][4] and BHMT2,[5][6] each encoded by a separate gene.
|
|
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.
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.