Fig. 3

RifQ specifically bound to the rifP promoter region. a EMSA analysis of RifQ binding of rifP promoter. From lane 1 to lane 4, the rifP probe was incubated with different concentrations of RifQ protein, i.e., 0, 0.2, 0.4 and 0.8 µM, respectively. In lanes 5 and 6, 50- and 100-folds of cold rifP probe was added into the reaction system for specific competition, respectively. b Characterization of the RifQ-protected DNA sequences through DNase I Footprinting assay. The rifP probe was incubated with (blue line) or without (red line) RifQ protein, and was then partially digested by DNase I. The RifQ-protected sequences were shown and the proposed RifQ binding sites were underlined. To prevent non-specific binding between RifQ and the DNA probes, sheared salmon sperm DNA was added in above reactions