Figure 5.

The transcription factor Rpa1489 binds the pucBA.b/e promoters. (A) Gel mobility shift assays with purified Rpa1489. The left lane (−) of each gel contained only ³²P-labeled probe, while the right lane (+) contained in addition 0.5 μM Rpa1489. PucBA from a to e represent the five pucBA promoter regions identified in Rps. palustris CGA009 strain (Larimer et al, 2004). (B) Binding affinity of unphosphorylated (blue curve) and phosphorylated (green curve) Rpa1489 to the pucBA.b promoter. Phosphorylated and unphosphorylated forms of Rpa1489 were obtained by incubating Rpa1489 with achromo-RpBphP4 for 30 min under reducing conditions in the presence or absence of ATP, respectively. (C) DNase I footprints of Rpa1489 and PpsR2 binding to the pucBA.b/e promoter regions. G+A ladder (lane a), control without protein (lane b), 1 μM Rpa1489 (lane c), 1 μM PpsR2 (lane d) (for color figure see online version).