Figure 7

Effect of arrangement of the DegU-recognition motifs in the sacB promoter. All fusions constructed by cloning various PCR products into pIS284 are derivatives of the S-WT fusion and the oligonucleotides used to construct are shown in Additional file 1. The β-galactosidase activities of sacB-lacZ were measured from cells grown in MC medium containing 1 M NaCl as described previously [45]. A and B. Filled circles, degS⁺ degU⁺; open circles, degS; squares, degU. The S-WT (A) and SC-IR2 (B) fusions are shown. C. The activities were assayed hourly from T0 through to T4. At least three independent assays were performed and the averages of the peak values are shown. Standard deviations did not exceed 10%. The "degS" and "degU" columns show the β-galactosidase activities of each fusion in the degS::Em^r and degU::Km^r backgrounds, respectively. Arrows above the sequences indicate the DegU-binding motifs.