Figure 1 .
(a) Gel retardation of PpbrAwith PbrR. Each reaction contained the same amount of 32P-end-labelled 296 bp PpbrA PCR product (60 fmol). Lanes 1, 9 and 10 contained no PbrR. PbrR concentrations in lanes 2–8 and 11–17 increase 2-fold from 0.3 to 19.2 pmol. Lanes 10–17 contained 10 μM Pb(II). (b) DNase I protection assay of PbrR bound to the 296 bp PCR product containing the PbrA promoter. Lanes AGCT, DNA sequence of the 296 bp PCR product pbrA promoter, using the pbrApe primer. Lanes 1 and 4, no added pbrR, lane 2 and 3 increasing amounts of added PbrR. (c) Diagram of the PpbrA promoter. The transcript start site is marked in bold and indicated with an arrow . The region of the promoter protected by PbrR from DNAase I digestion is marked with a box. The predicted −35 and −10 sequences are marked in bold, and the dyad symmetrical sequence is marked with arrows.
Hobman et al. BMC Microbiology 2012 12:109 doi:10.1186/1471-2180-12-109