Structural highlights
Function
[BHMT1_HUMAN] Involved in the regulation of homocysteine metabolism. Converts betaine and homocysteine to dimethylglycine and methionine, respectively. This reaction is also required for the irreversible oxidation of choline.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Betaine-homocysteine methyl transferase (BHMT) catalyzes the synthesis of methionine from betaine and homocysteine (Hcy), utilizing a zinc ion to activate Hcy. BHMT is a key liver enzyme that is important for homocysteine homeostasis. X-ray structures of human BHMT in its oxidized (Zn-free) and reduced (Zn-replete) forms, the latter in complex with the bisubstrate analog, S(delta-carboxybutyl)-L-homocysteine, were determined at resolutions of 2.15 A and 2.05 A. BHMT is a (beta/alpha)(8) barrel that is distorted to construct the substrate and metal binding sites. The zinc binding sequences G-V/L-N-C and G-G-C-C are at the C termini of strands beta6 and beta8. Oxidation to the Cys217-Cys299 disulfide and expulsion of Zn are accompanied by local rearrangements. The structures identify Hcy binding fingerprints and provide a prototype for the homocysteine S-methyltransferase family.
Betaine-homocysteine methyltransferase: zinc in a distorted barrel.,Evans JC, Huddler DP, Jiracek J, Castro C, Millian NS, Garrow TA, Ludwig ML Structure. 2002 Sep;10(9):1159-71. PMID:12220488[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Evans JC, Huddler DP, Jiracek J, Castro C, Millian NS, Garrow TA, Ludwig ML. Betaine-homocysteine methyltransferase: zinc in a distorted barrel. Structure. 2002 Sep;10(9):1159-71. PMID:12220488
