During stationary phase, binds the chromosome non-specifically, forming a highly ordered and stable dps-DNA co-crystal within which chromosomal DNA is condensed and protected from diverse damages. It protects DNA from oxidative damage by sequestering intracellular Fe(2+) ion and storing it in the form of Fe(3+) oxyhydroxide mineral, which can be released after reduction. One hydrogen peroxide oxidizes two Fe(2+) ions, which prevents hydroxyl radical production by the Fenton reaction. Dps also protects the cell from UV and gamma irradiation, iron and copper toxicity, thermal stress and acid and base shocks. Also shows a weak catalase activity. 2 Fe(2+) + 2 H(+) + H2O2 = 2 Fe(3+) + 2 H2O Homododecamer. The 12 subunits form a hollow sphere into which the mineral iron core of up to 500 Fe(3+) can be deposited. Induced by RpoS and IHF in the early stationary phase. Induced by OxyR in response to oxidative stress during exponential phase. ClpXP probably directly regulate proteolysis of dps during exponential phase. ClpAP seems to play an indirect role in maintaining ongoing dps synthesis during stationary phase. 12 dinuclear ferroxidase centers are located at the interfaces between subunits related by 2-fold symmetry axes. The lysine-rich N-terminus is required for self-aggregation as well as for dps-driven DNA condensation. Belongs to the Dps family.