FIG. 7.

DNA binding of PilR to the fimA promoter region. (A) A 359-bp ³²P-labeled DNA fragment located upstream of the fimA promoter was incubated with PilR and increasing concentrations (0.005, 0.05, and 0.5 fmol) of unlabeled competitor DNA and analyzed using gel mobility shift analysis on 4% polyacrylamide gels. Lanes are as follows: NP, no protein; P, 150 nM PilR and no competitor DNA and increasing concentrations (10 to 10,000 times) of specific competitor DNA, compared to labeled DNA. The locations of free DNA (F) and protein-DNA complexes (C) are indicated. (B) Gel mobility shift analysis of PilR and the fimA promoter region incubated with increasing concentrations of nonspecific unlabeled competitor DNA.