FIG. 8.

Binding of PhoP to the pst promoter. Electromobility shift assays were carried out with 0.5 ng 3′ DIG-labeled pst promoter fragment P3 (A), fragment P1 (B), and fragment P4 (C) in the presence of 5 mM ATP. Fragments were incubated without protein (lane 1), with 5 μM Strep-Tag-PhoP (lane 2), with 5 μM Strep-Tag-PhoP and 1.5 μM MBP-*PhoR (lane 3), or with 5 μM Strep-Tag-PhoP, 1.5 μM MBP-*PhoR, and 100 ng unlabeled fragment. (D) As negative controls, unspecific DIG-labeled DNA fragments were incubated under the same conditions without protein (lane 1) and with 5 μM Strep-Tag-PhoP and 1.5 μM MBP-*PhoR (lane 2). Additionally DIG-labeled fragment P3 was incubated without protein (lane 3) and with 3 μM MBP-*PhoR (lane 4).