The methionine sulfoxide reductases: Catalysis and substrate specificities.
Fiche publication
Date publication
juin 2008
Auteurs
Membres identifiés du Cancéropôle Est :
Pr BOSCHI-MULLER Sandrine
Tous les auteurs :
Boschi-Muller S, Gand A, Branlant G
Lien Pubmed
Résumé
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.
Référence
Arch Biochem Biophys. 2008 Jun 15;474(2):266-73