Fig 2.
DNA binding properties of purified ExsA and LcrF. EMSAs were performed using radiolabeled probes derived from the ExsA-dependent PexsC (A and B), PexoT (C and D), and PexsD (E and F) promoters. A nonspecific probe (Non-Sp) derived from the algD promoter region was included in all binding reactions as a negative control. Probes (0.05 nM each) were incubated in the absence or presence of 11, 23, 45, 90, 180, or 360 nM ExsA (A, C, and E) or LcrF (B, D, and F) for 15 min at 25°C. Samples were analyzed by native polyacrylamide gel electrophoresis and phosphorimaging. The positions of shift products 1 and 2 are indicated. The asterisk indicates background shifting of the nonspecific probe by LcrF.