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 Q9NZV6
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 Q9NZV6
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)

Q9NZV6
MSRB1_HUMAN
Homo sapiens
Methionine-R-sulfoxide reductase B1

PDB Structure

PDB 3MAO
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Crystal Structure of Human Methionine-R-Sulfoxide Reductase B1 (MsrB1)
Chaikuad, A., Shafqat, N., Yue, W.W., Savitsky, P., Krojer, T., Ugochukwu, E., Muniz, J.R.C., Pike, A.C.W., von Delft, F., H Arrowsmith, C., Edwards, A.M., Weigelt, J., Bountra, C., Oppermann, U., Structural Genomics Consortium (SGC)
To be Published