CATH Classification

Domain Context

CATH Clusters

Superfamily Cobalamin-dependent Methionine Synthase, domain 2
Functional Family

Enzyme Information

2.1.1.13
Methionine synthase.
based on mapping to UniProt P13009
5-methyltetrahydrofolate + L-homocysteine = tetrahydrofolate + L-methionine.
-!- The enzyme becomes inactivated occasionally during its cycle by oxidation of Co(I) to Co(II). -!- Reactivation by reductive methylation is catalyzed by the enzyme itself, with S-adenosyl-L-methionine as the methyl donor and a reducing system. -!- For the mammalian enzyme, the reducing system involves NADPH and EC 1.16.1.8. -!- In bacteria, the reducing agent is flavodoxin, and no further catalyst is needed (the flavodoxin is kept in the reduced state by NADPH and EC 1.18.1.2). -!- Acts on the monoglutamate as well as the triglutamate folate, in contrast with EC 2.1.1.14, which acts only on the triglutamate.

UniProtKB Entries (1)

P13009
METH_ECOLI
Escherichia coli K-12
Methionine synthase

PDB Structure

PDB 3BUL
External Links
Method X-RAY DIFFRACTION
Organism Escherichia
Primary Citation
A disulfide-stabilized conformer of methionine synthase reveals an unexpected role for the histidine ligand of the cobalamin cofactor.
Datta, S., Koutmos, M., Pattridge, K.A., Ludwig, M.L., Matthews, R.G.
Proc.Natl.Acad.Sci.Usa