Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
5-methyltetrahydrofolate-homocysteine methyltransferase
Introduction
5-Methyltetrahydrofolate-homocysteine methyltransferase or (MTR) is an enzyme responsible for the production of methionine from homocysteine. MTR forms part of the S-adenosyl methionine cycle and is also called methionine synthase.[1]
Function
Function
MTR contains the cofactor – methylcobalamin (MeB12) and uses the substrates N5-methyl-tetrahydrofolate (N5-methyl-THF) and homocysteine.
The enzyme works in two steps in a ping-pong reaction. First, methylcobalamin is formed by a methyl group transfer from N5-mTHF with formation of MeB12 and tetrahydrofolate (THF). In the second step, MeB12 transfers this methyl group to (homocysteine), regenerating the cofactor cobalamin and releasing the product methionine
References
References
- ↑ Banerjee RV, Matthews RG (1990). “Cobalamin-dependent methionine synthase” (PDF). FASEB J. 4 (5): 1450–9. PMID 2407589.
External links
External links
- ENZYME: EC 2.1.1.13
- 5-Methyltetrahydrofolate-Homocysteine+S-Methyltransferase at the US National Library of Medicine Medical Subject Headings (MeSH)