CATH Classification

Domain Context

CATH Clusters

Superfamily Peptide methionine sulfoxide reductase.
Functional Family methionine-R-sulfoxide reductase B1

Enzyme Information

1.8.4.12
Peptide-methionine (R)-S-oxide reductase.
based on mapping to UniProt Q9JLC3
Peptide-L-methionine + thioredoxin disulfide + H(2)O = peptide-L- methionine (R)-S-oxide + thioredoxin.
-!- The reaction occurs in the reverse direction to that shown above. -!- Exhibits high specificity for reduction of the R-form of methionine S-oxide, with higher activity being observed with L-methionine S-oxide than with D-methionine S-oxide. -!- While both free and protein-bound methionine (R)-S-oxide act as substrates, the activity with the peptide-bound form is far greater. -!- Plays a role in preventing oxidative-stress damage caused by reactive oxygen species by reducing the oxidized form of methionine back to methionine and thereby reactivating peptides that had been damaged. -!- The reaction proceeds via a sulfenic-acid intermediate. -!- For MsrB2 and MsrB3, thioredoxin is a poor reducing agent but thionein works well.
1.8.4.14
L-methionine (R)-S-oxide reductase.
based on mapping to UniProt Q9JLC3
L-methionine + thioredoxin disulfide + H(2)O = L-methionine (R)-S-oxide + thioredoxin.
-!- Unlike EC 1.8.4.12 this enzyme cannot use peptide-bound methionine (R)-S-oxide as a substrate. -!- Differs from EC 1.8.4.13, in that L-methionine (S)-S-oxide is not a substrate. -!- Formerly EC 1.8.4.5.

UniProtKB Entries (1)

Q9JLC3
MSRB1_MOUSE
Mus musculus
Methionine-R-sulfoxide reductase B1

PDB Structure

PDB 2KV1
External Links
Method SOLUTION NMR
Organism
Primary Citation
Insights into function, catalytic mechanism, and fold evolution of selenoprotein methionine sulfoxide reductase B1 through structural analysis
Aachmann, F.L., Sal, L.S., Kim, H.Y., Marino, S.M., Gladyshev, V.N., Dikiy, A.
J.Biol.Chem.