Methionine sulfoxide reductase B (MsrB) from Escherichia coli is a member of the msrB Met sulfoxide reductase family. The E.coli msrB carries out the reduction of methionine-R-sulfoxide to methionine. msrB possess a metal binding site composed of 2 CXXC motifs. The bound metal (zinc or iron) may stabilize the conformation of the enzymes.
MSRB produced in E.Coli is a single, non-glycosylated polypeptide chain containing 157 amino acids (1-137 a.a.) and having a molecular mass of 17.6kDa. MSRB is fused to a 20 amino acid His-tag at N-terminus & purified by proprietary chromatographic techniques.