DNA binding assays with 10 nM dsmntH26 titrated with MntR in presence of 1000 μM (○), 100 μM (■), or 10 μM (×) of metal ion. Results are shown for Cd2+ (top), Co2+ (middle), and Mn2+ (bottom). Buffer = 20 mM HEPES pH 7.2@4 °C, 500 mM NaCl, 5% (v/v) glycerol. T = 25 °C.