MsrB – L-methionine-R-sulfoxide reductase

Name
WID	MsrB
Name	L-methionine-R-sulfoxide reductase
Cross references	EC: 1.8.4.6, BiGG: METSOXR2, KEGG: R04120

Classification
Type	chemical

Reaction
Stoichiometry	[c]: H2O + MET + MG_124_MONOMER_ox ⇔ METSOXRL + MG_124_MONOMER

Catalysis
Enzyme	MG_448_MONOMER [c]

Energetics
Is spontaneous (pH 7.5, 25C, I = 0)	False

Kinetics
Forward kinetics	V_max = 66.0 1/min

Associations
Process	Process_Metabolism

Comments
Comments	reactive oxygen species (eg. Superoxide, hydroxyl radical, hydrogen peroxide, singlet oxygen) can oxidize methionine to methionine sulfoxide; possibly > 30% of methionine residues are oxidized [PUB_0133]. catalyzes thioredoxin-dependent reduction of free and protein-bound Met(O) to methionine [PUB_0129]; S enantiomer selectivity [PUB_0131]; required for virulence, influences in cytadherence [PUB_0132]. Boschi-Muller et al reported that thioredoxin and Zn2+ are required as cofactors [PUB_0131]. Kinetic parameters observed by Boschi-Muller et al: Vmax=1.1 1/s [PUB_0131].
References	Boschi-Muller S, Olry A, Antoine M, Branlant G. The enzymology and biochemistry of methionine sulfoxide reductases. Biochim Biophys Acta 1703, 231-8 (2005). WholeCell: PUB_0131, PubMed: 15680231 Brot N, Weissbach H. Peptide methionine sulfoxide reductase: biochemistry and physiological role. Biopolymers 55, 288-96 (2000). WholeCell: PUB_0133, PubMed: 11169920 Dhandayuthapani S, Blaylock MW, Bebear CM, Rasmussen WG, Baseman JB. Peptide methionine sulfoxide reductase (MsrA) is a virulence determinant in Mycoplasma genitalium. J Bacteriol 183, 5645-50 (2001). WholeCell: PUB_0132, PubMed: 11544227 Moskovitz J, Bar-Noy S, Williams WM, Requena J, Berlett BS, Stadtman ER. Methionine sulfoxide reductase (MsrA) is a regulator of antioxidant defense and lifespan in mammals. Proc Natl Acad Sci U S A 98, 12920-5 (2001). WholeCell: PUB_0129, PubMed: 11606777

Metadata
Created	2012-10-01 15:08:52
Last updated	2012-10-01 15:17:24