Crystal structure of peroxide stress regulator from Streptococcus pyogenes provides functional insights into the mechanism of oxidative stress sensing.

ABSTRACT: Regulation of oxidative stress responses by the peroxide stress regulator (PerR) is critical for the in vivo fitness and virulence of group A Streptococcus. To elucidate the molecular mechanism of DNA binding, peroxide sensing, and gene regulation by PerR, we performed biochemical and structural characterization of PerR. Sequence-specific DNA binding by PerR does not require regulatory metal occupancy. However, metal binding promotes higher affinity PerR-DNA interactions. PerR metallated with iron directly senses peroxide stress and dissociates from operator sequences. The crystal structure revealed that PerR exists as a homodimer with two metal-binding sites per subunit as follows: a structural zinc site and a regulatory metal site that is occupied in the crystals by nickel. The regulator

SUBMITTER: Makthal N 

PROVIDER: S-EPMC3689973 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature