FIGURE 5.

Electrophoretic mobility shift assays confirmed direct binding of QsrR to the expR promoter (pexpR). pexpR is a 286 bp DNA fragment from the translational start codon of gene expR. Each lane contained 0.005 nM of labeled pexpR. The labeled pexpR and a ∼100-fold excess of the unlabeled pexpR were used in competitive assays. Labeled non-specific DNA from Streptomyces avermitilis was used as negative control. The amount of His₆-QsrR added in each lane were 0 μM, 0.92 Mm, 1.65 μM, 2.38 μM, 3.3 μM, 4.77 μM, 4.77 μM, and 4.77 μM, respectively.