FIG. 2.

DNA binding activities of unphosphorylated SaeR (A), the C-terminal effector domain of SaeR (B), and phosphorylated SaeR (C) to the P1 promoter region. In a typical assay, 2 ng of a γ-³²P-end-labeled P1 promoter fragment was incubated with the indicated concentration of protein in the presence of 3 μg/ml salmon sperm DNA at room temperature for 15 min. Free DNA is indicated by a white arrowhead, and bound DNA is indicated by a black arrowhead. SaeR, unphosphorylated SaeR; SaeR^C, the C-terminal effector domain of SaeR; P-SaeR, phosphorylated SaeR; + cold DNA, addition of a 10-fold excess of unlabeled DNA.