Kineococcus radiotolerans Dps forms a heteronuclear Mn-Fe ferroxidase center that may explain the Mn-dependent protection against oxidative stress

► Mn(II) binds to the A site of the binuclear K. radiotolerans Dps ferroxidase center. ► A heterometallic ferroxidase center is formed when Fe(II) binds to the B site. ► During the catalyzed Fe(II) oxidation Mn(II) participates in redox cycling. ► Both the Mn/Fe and the canonic Fe/Fe ferroxidase centers limit OH release in solution. ► Mn(II) participation in redox cycling of KrDps may explain the Mn-dependent protection against oxidative stress.