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. 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. Belongs to the Dps family.