Protects DNA from oxidative damage by sequestering intracellular Fe(2+) ion and storing it in the form of Fe(3+) oxyhydroxide mineral (By similarity). It binds and incorporates Fe(2+) ion. Effectively inhibits hydroxyl radical formation by the Fenton reaction and is essential for colony formation in the presence of air. Is also able to bind zinc ion. Does not bind DNA. 2 Fe(2+) + 2 H(+) + H2O2 = 2 Fe(3+) + 2 H2O Homododecamer (Probable). The oligomer forms a hollow sphere and can store up to 480 Fe(3+). Induced by air. 12 di-nuclear ferroxidase centers are located at the interfaces between subunits related by 2-fold symmetry axes. Belongs to the Dps family.