Homologous Superfamily

Peptide methionine sulphoxide reductase MsrA superfamily (IPR036509)

Short name: Met_Sox_Rdtase_MsrA_sf

Overlapping entries


Peptide methionine sulphoxide reductase (Msr) reverses the inactivation of many proteins due to the oxidation of critical methionine residues by reducing methionine sulphoxide, Met(O), to methionine [PMID: 10841552]. It is present in most living organisms, and the cognate structural gene belongs to the so-called minimum gene set [PMID: 8994848, PMID: 8816789].

The domains MsrA and MsrB reduce different epimeric forms of methionine sulphoxide. This group represent MsrA, the crystal structure of which has been determined in a number of organisms. In Mycobacterium tuberculosis, the MsrA structure has been determined to 1.5 Angstrom resolution [PMID: 12837786]. In contrast to the three catalytic cysteine residues found in previously characterised MsrA structures, M. tuberculosis MsrA represents a class containing only two functional cysteine residues. The overall structure shows no resemblance to the structures of MsrB (IPR002579) from other organisms; though the active sites show approximate mirror symmetry. In each case, conserved amino acid motifs mediate the stereo-specific recognition and reduction of the substrate.

In a number of pathogenic bacteria including Neisseria gonorrhoeae, the MsrA and MsrB domains are fused; the MsrA being N-terminal to MsrB. This arrangement is reversed in Treponema pallidum. In N. gonorrhoeae and Neisseria meningitidis a thioredoxin domain is fused to the N terminus. This may function to reduce the active sites of the downstream MsrA and MsrB domains.

GO terms

Biological Process

GO:0055114 oxidation-reduction process

Molecular Function

GO:0008113 peptide-methionine (S)-S-oxide reductase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.