![]() These data indicate that an iron-binding protein, Dpr, provides protection from hydrogen peroxide stress by preventing the Fenton reaction, and Dpr was identified as a novel stress protein that protects against several stresses in group A streptococci. Recombinant Dpr protein was purified and showed iron-binding activity, whereas no DNA-binding activity was found. The dpr mutant showed high sensitivity to iron and zinc but not to manganese, copper, nickel, and calcium. The growth of the dpr mutant was slower than that of the wild-type strain in iron-limiting conditions. The dpr mutant also showed a low survival rate in the long-term stationary phase, when it was treated with extreme acids, and under alkaline pH conditions compared to the wild-type strain. Pretreatment with the iron chelator deferoxamine mesylate rescued the survival activity of the mutant under oxidative stress conditions. The dpr mutant was more sensitive to H 2O 2, and complementation could partially restore the defect in the mutant. A dpr deletion mutant was constructed by double-crossover mutagenesis. ![]() ![]() The aim of this study was to characterize the dpr gene and its role in dealing with different stresses. ![]() One of the stress proteins of this organism, peroxide resistance protein (Dpr), has been studied to examine its role in resistance to hydrogen peroxide, but the protective mechanism of Dpr is not clear. Streptococcus pyogenes does not produce catalase, but it can grow in aerobic environments and survive in the presence of peroxide.
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