Download MendeleyCrystal structure of the homocysteine methyltransferase MmuM from Escherichia coli.
Li, K., Li, G., Bradbury, L.M., Hanson, A.D., Bruner, S.D.(2016) Biochem J 473: 277-284
- PubMed: 26564203
- DOI: https://doi.org/10.1042/BJ20150980
- Primary Citation of Related Structures:
5DML, 5DMM, 5DMN - PubMed Abstract:
Homocysteine S-methyltransferases (HMTs, EC 2.1.1.0) catalyse 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 micro-organisms, 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 zinc-binding motif in the enzyme active site. In the present study, we demonstrate 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.
Organizational Affiliation:
Department of Chemistry, University of Florida, Gainesville, FL 32611, U.S.A.
