5DML

Crystal Structure of the Homocysteine Methyltransferase MmuM from Escherichia coli, Oxidized form

Summary for 5DML

• Entry DOI: 10.2210/pdb5dml/pdb
• Related: 5DMM 5DMN
• Descriptor: Homocysteine S-methyltransferase, CHLORIDE ION (3 entities in total)
• Functional Keywords: homocysteine methyltransferase, transferase
• Biological source: Escherichia coli (strain K12)
• Total number of polymer chains: 1
• Total formula weight: 33493.21

Authors

Li, K.,Li, G.,Bradbury, L.M.T.,Andrew, H.D.,Bruner, S.D. (deposition date: 2015-09-09, release date: 2015-11-25, Last modification date: 2024-10-30)

Primary citation

Li, K.,Li, G.,Bradbury, L.M.,Hanson, A.D.,Bruner, S.D.
Crystal structure of the homocysteine methyltransferase MmuM from Escherichia coli.
Biochem.J., 473:277-284, 2016

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.

PubMed: 26564203
DOI: 10.1042/BJ20150980

Experimental method

X-RAY DIFFRACTION (2.452 Å)