FIG. 7.

DNase I footprinting of LigR binding to the ligK and ligJ promoter regions. The 238-bp fragment or the 251-bp fragment containing the ligK (A) or ligJ (B) promoter region, respectively, was labeled with DIG on the coding (left) or noncoding (right) strands. The presence (+) or absence (−) of purified LigR (100 nM), PCA, and GA in the reaction mixture is indicated. Inducers were added at a concentration of 1 mM in each reaction. Thicker bars indicate strong protection by LigR, and thinner bars show weakly protected regions. The DNase I-hypersensitive sites are shown with arrowheads. The colors of bars and arrowheads indicate the reactions performed in the absence (black) or presence (gray) of PCA or GA, respectively.