Fig. (2) A), Purified recombinant His-tagged FitR protein analyzed by a 15% SDS-PAGE gel. Lane1, His-tagged FitR; lane 2, standard protein Marker. B), FitR binds to the fit promoter. All the lanes contained 3ng end-labeled fit promoter DNA. Lane 1 contained no protein; lanes 2-5 contained 100, 10, 20, and 50ng purified FitR, respectively. Lane 6 contained 50ng FitR and 150ng unlabeled fit promoter DNA. S and F indicate FitR bound and free DNA bands, respectively.