5dmn

Publication Abstract from PubMed

Homocysteine S -methyltransferases (HMTs, EC 2.1.1.0) catalyze the conversion of homocysteine to methionine using S -methylmethionine or S -adenosylmethionine as the methyl donor. HMTs play an important role in methionine biosynthesis and are widely distributed among microorganisms, plants, and animals. Additionally, HMTs play a role in metabolite repair of S -adenosylmethionine by removing an inactive diastereomer from the pool. The mmuM gene product from Escherichia coli is an archetypal HMT family protein and contains a predicted Zn-binding motif in the enzyme active site. Here we present X-ray structures for MmuM in oxidized, apo, and metallated forms, representing the first such structures for any member of the HMT family. The structures reveal a metal/substrate binding pocket distinct from those in related enzymes. The presented structure analysis and modelling of co-substrate interactions provide valuable insight into the function of MmuM in both methionine biosynthesis and cofactor repair.

Crystal structure of the homocysteine methyltransferase MmuM from Escherichia coli.,Li K, Li G, Bradbury LM, Hanson AD, Bruner SD Biochem J. 2015 Nov 12. pii: BJ20150980. PMID:26564203^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.