Protein Family Models

This enzyme repairs damaged proteins. Methionine sulfoxide in proteins is reduced to methionine. [1]. 8755589. Peptide methionine sulfoxide reductase contributes to the maintenance of adhesins in three major pathogens. Wizemann TM, Moskovitz J, Pearce BJ, Cundell D, Arvidson CG, So M, Weissbach H, Brot N, Masure HR;. Proc Natl Acad Sci USA 1996;93:7985-7990. [2]. 8700890. Cloning the expression of a mammalian gene involved in the reduction of methionine sulfoxide residues in proteins. Moskovitz J, Weissbach H, Brot N;. Proc Natl Acad Sci U S A 1996;93:2095-2099. (from Pfam)

Date:

2024-10-16

Methionine sulfoxide reduction is an important process, by which cells regulate biological processes and cope with oxidative stress. MsrA, a protein involved in the reduction of methionine sulfoxides in proteins, has been known for four decades and has been extensively characterised with respect to structure and function. However, recent studies revealed that MsrA is only specific for methionine-S-sulfoxides. Because oxidised methionines occur in a mixture of R and S isomers in vivo, it was unclear how stereo-specific MsrA could be responsible for the reduction of all protein methionine sulfoxides. It appears that a second methionine sulfoxide reductase, SelR , evolved that is specific for methionine-R-sulfoxides, the activity that is different but complementary to that of MsrA. Thus, these proteins, working together, could reduce both stereoisomers of methionine sulfoxide. This domain is found both in SelR proteins and fused with the peptide methionine sulfoxide reductase enzymatic domain Pfam:PF01625. The domain has two conserved cysteine and histidines. The domain binds both selenium and zinc [2]. The final cysteine is found to be replaced by the rare amino acid selenocysteine in some members of the family [1]. This family has methionine-R-sulfoxide reductase activity [2]. [1]. 10608886. Novel selenoproteins identified in silico and in vivo by using a conserved RNA structural motif. Lescure A, Gautheret D, Carbon P, Krol A;. J Biol Chem 1999;274:38147-38154. [2]. 11929995. Selenoprotein R is a zinc-containing stereo-specific methionine sulfoxide reductase. Kryukov GV, Kumar RA, Koc A, Sun Z, Gladyshev VN;. Proc Natl Aca. TRUNCATED at 1650 bytes (from Pfam)

Date:

2024-10-16

This HMM describes peptide methionine sulfoxide reductase (MsrA), a repair enzyme for proteins that have been inactivated by oxidation. The enzyme from E. coli is coextensive with this model and has enzymatic activity. However, in all completed genomes in which this module is present, a second protein module, described in TIGR00357, is also found, and in several cases as part of the same polypeptide chain: N-terminal to this module in Helicobacter pylori and Haemophilus influenzae (as in PilB of Neisseria gonorrhoeae) but C-terminal to it in Treponema pallidum. PilB, containing both domains, has been shown to be important for the expression of adhesins in certain pathogens.

Gene:

msrA

Date:

2021-06-02

The stereospecific enzyme peptide-methionine (R)-S-oxide reductase MsrB co-occurs with MsrA, which reduces the (S) form, occasionally fused with MsrA in a bifunctional protein. It provides protection against oxidative stress.

Gene:

msrB

Date:

2023-06-23