Figure 4.

No regulatory interaction between OmpR and CRP. For RT-PCR and LacZ fusion experiments, we show the mean fold increase of the mRNA level (RT-PCR) or the detecting promoter activity (LacZ fusion) for crp or ompR in ΔompR or Δcrp relative to WT. For primer extension experiments, we show the primer extension product for crp or ompR in WT or Δcrp or ΔompR, and DNA sequences on the right side from the bottom (5') to the top (3'); the transcription start sites are underlined. For DNase I footprinting experiments, the labeled DNA probe of crp or ompR was incubated with 0, 5, 10, 15, and 20 pmol of purified His-CRP (with addition of 2 mM cAMP) or His-OmpR (in the presence of 25 mM acetyl phosphate) in lanes 1 to 5, respectively. No footprint region was detected.