CATH Classification

Domain Context

CATH Clusters

Superfamily Vitamin B12-dependent methionine synthase, activation domain
Functional Family Methionine synthase

Enzyme Information
Methionine synthase.
based on mapping to UniProt Q99707
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 -!- 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 -!- Acts on the monoglutamate as well as the triglutamate folate, in contrast with EC, which acts only on the triglutamate.

UniProtKB Entries (1)

Homo sapiens
Methionine synthase

PDB Structure

External Links
Organism Escherichia
Primary Citation
Crystal structure and solution characterization of the activation domain of human methionine synthase
Wolthers, K.R., Toogood, H.S., Jowitt, T.A., Marshall, K.R., Leys, D., Scrutton, N.S.
Febs J.