Figure 4.

Activation of the p_R promoter by DnaA protein in vitro in the presence (•) and absence (▴) of the DnaA-binding sequence downstream of the promoter. Template DNA (0.5 μg) and indicated amounts of DnaA protein were used. Similar results were obtained when different templates, all derived from p_R–HG and its analogue bearing the scrambled DnaA box, were used: EcoRI–Bsu36I fragments, the plasmids linearized with Bsu36I, and the plasmids linearized with ClaI (the lengths of p_R-derived transcripts were 512, 512 and 1112 nucleotides, respectively). EcoRI site is located upstream of p_R and Bsu36I and ClaI sites are located in the lacZ gene of plasmid p_R–HG and its analogue. Average data from seven experiments are presented; appropriate bands on the autoradiograms were quantified by densitometry.