FIG. 8.

DNase I footprint assay with CRP and CitB_His. The 348 bp MluI-SphI fragment covering the citC-citS intergenic region was labeled by fill-in of the 3′-recessed ends created by MluI with Klenow polymerase. Lane 1, G+A sequencing ladder; lane 2, 0.4 μM CitB_His; lane 3, 1.6 μM CitB_His; lane 4, no protein; lane 5, 3.7 μM CRP; lane 6, 2.0 μM CRP plus 0.4 μM CitB_His; lane 7, 2.0 μM CRP plus 1.6 μM CitB_His. The hypersensitive sites (indicated with asterisks) are located at positions −47 relative to the citS transcription start site (top) and at −35 and −46 relative to the citC transcription start site (bottom).