Catalytic Mechanism of Sulfiredoxin from Saccharomyces cerevisiae Passes through an Oxidized Disulfide Sulfiredoxin Intermediate That Is Reduced by Thioredoxin

• DOI: 10.1074/jbc.m109.035352
• Publication Date: 2009-10-01T00:12:46Z
• Authors: Xavier Roussel; Alexandre Kriznik; Christelle Richard; Sophie Rahuel-Cle...; Guy Branlant
• Keywords: Sulfenic acid; Peroxiredoxin; Moiety

Sulfiredoxin catalyzes the ATP-dependent reduction of overoxidized eukaryotic 2-Cys peroxiredoxin PrxSO(2) into sulfenic PrxSOH. Recent mechanistic studies on sulfiredoxins have validated a catalytic mechanism that includes formation phosphoryl intermediate sulfinyl moiety PrxSO(2), followed by an attack cysteine sulfiredoxin leads to thiosulfinate PrxSO-S-sulfiredoxin. Formation this implies recycling reduced form. In study, we investigated how reductase activity Saccharomyces cerevisiae is regenerated. The results show oxidized under disulfide state formed between Cys(84) and Cys(48). This species shown be catalytically competent along sulfiredoxin-recycling process selectively thioredoxin. lack Cys(48) in mammalian low efficiency thioredoxin suggest mammals different from cerevisiae.