EMSA using labeled probe b-WT and increasing concentrations of recombinant BpaB proteins based on sequences of B31 plasmids cp32-1, lp56, cp9-1 and lp38. For all EMSAs, lane 1 contained DNA without protein. (A) Lanes 2–12 contained in addition 0.033, 0.066, 0.099, 0.13, 0.17, 0.20, 0.23, 0.26, 0.30, 0.33 and 0.40 µM recombinant BpaB321 protein, respectively. (B) Lanes 2–12 contained 0.0048, 0.012, 0.024, 0.048, 0.097, 0.15, 0.19, 0.24, 0.29, 0.34 and 0.39 µM recombinant BpaB56 protein, respectively. (C) Lanes 2–12 contained 0.084, 0.17, 0.25, 0.34, 0.42, 0.50, 0.59, 0.67, 0.75, 0.84 and 1.00 µM recombinant BpaB9 protein, respectively. (D) Lanes 2–12 contained 0.069, 0.14, 0.21, 0.28, 0.35, 0.42, 0.48, 0.55, 0.62, 0.69 and 0.83 µM recombinant BpaB38 protein, respectively. Note that some of the higher-order DNA–protein complexes do not always resolve crisply, and appear faint or as smears in EMSAs [e.g. the upper EMSA bands in lane 12 of (C)].