Manganese-dependent repressor that controls a regulon of oxidative stress resistance and iron-storage proteins. Regulates expression of genes encoding antioxidant proteins, such as katA, ahpCF, bcp and trxB. Also regulates expression of the iron-storage protein ftn, the ferritin-like protein mrgA, the ferric uptake regulator fur, the manganese transporter operon mntABC, and its own expression. May act as a hydrogen peroxide and organic hydroperoxide sensor. Required for full virulence in a murine skin abscess model of infection. Autoregulated. Induced by low levels of hypochlorous acid via superoxide dismutase inactivation. Belongs to the Fur family.