Hydrogen and organic peroxide sensor. Represses the expression of a regulon of peroxide-inducible genes such as katA, ahpC, ahpF, the heme biosynthesis operon (hemAXCDBL), fur, perR, zosA and mrgA. Binds 1 Mn(2+) or Fe(2+) ion per subunit. Binds 1 zinc ion per subunit. Homodimer. Possibly oxidized on a cysteine residue; the Cys-SOH formed in response to oxidative signaling may rapidly react with a Cys-SH to form a disulfide bond, leading to the loss of metal ion and inactivation of repressor function. Oxidized PerR can be further reduced by thiol reductants and repressor activity restored. Belongs to the Fur family.