Figure 4. HilE dampens SPI1 gene expression.

(A) Comparison of time-course dynamics for P_hilD (pSS074, black) and P_hilA (pSS077, red) promoter activities in wild type (solid lines) and a ΔhilE mutant (CR361, dashed lines) as determined using luciferase transcriptional reporters. (B) Comparison of P_hilA (pSS055) promoter activities in wild type (black) and a ΔhilE mutant (CR361, grey) as determined using GFP transcriptional reporters and flow cytometry. Similar results are also observed with the P_hilD promoter, though the phenotypic effect is much larger (Figure S4). Experiments were performed as described in Figure 1 .