The methionine sulfoxide reductases: Catalysis and substrate specificities.
Oxidation of Met residues in proteins leads to the formation of methionine sulfoxides (MetSO). Methionine sulfoxide reductases (Msr) are ubiquitous enzymes, which catalyze the reduction of the sulfoxide function of the oxidized methionine residues. In vivo, the role of Msrs is described as essential in protecting cells against oxidative damages and to play a role in infection of cells by pathogenic bacteria. There exist two structurally-unrelated classes of Msrs, called MsrA and MsrB, with opposite stereoselectivity towards the S and R isomers of the sulfoxide function, respectively. Both Msrs present a similar three-step catalytic mechanism. The first step, called the reductase step, leads to the formation of a sulfenic acid on the catalytic Cys with the concomitant release of Met. In recent years, significant efforts have been made to characterize structural and molecular factors involved in the catalysis, in particular of the reductase step, and in structural specificities.
Boschi-Muller
Sandrine
S
UMR 7567 CNRS-UHP--Maturation des ARN et Enzymologie Moléculaire, Nancy Université, BP 239, 54506 Vandoeuvre-lès-Nancy, France. sandrine.boschi@maem.uhp-nancy.fr
Gand
Adeline
A
Branlant
Guy
G
D000818:Animals; D002384:Catalysis; D002417:Cattle; D003545:Cysteine / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D007700:Kinetics; D008715:Methionine / Q000031:analogs & derivatives* / Q000378:metabolism*; D051150:Methionine Sulfoxide Reductases; D009169:Mycobacterium tuberculosis / Q000201:enzymology; D009343:Neisseria / Q000201:enzymology; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D032107:Populus / Q000201:enzymology; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000378:metabolism
D013438:Sulfhydryl Compounds; D008715:Methionine; D010088:Oxidoreductases; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase; D003545:Cysteine; C013111:methionine sulfoxide