FIG. 1.

Effect of the phosphorylation of UhpA on binding to sites in the uhpT promoter. Fractional occupancy represents the intensity of DNase cleavage of bands in the strong (positions −76 to −69, circles) and weak (positions −47 to −31, squares) sites in the uhpT promoter, corrected for background and normalized to the intensity of nearby bands. The UhpA protein was added at the indicated concentrations in its native state (open symbols) or after phosphorylation by incubation with acetyl phosphate (solid symbols). The inset shows the binding data plotted logarithmically.