FIGURE 6.

PapX repression of flhDC-lacZ promoter fusions. Nested deletions of the flhDC promoter were fused to promoterless lacZ in pRS551. Deletions contained progressively less of the 5′-end of the promoter. pRS551-flhDC promoter constructs were transformed into CFT073 WT (black bars) or CFT073 ΔpapX (white bars). No significant difference (NS, p > 0.05) was observed in β-galactosidase activity as assessed by a Miller assay between CFT073 WT and CFT073 ΔpapX using a one-tailed t test when only the first 360 bases of the flhDC promoter was included. Significant differences (*, p < 0.025) were observed when 501 bases or more of the flhDC promoter was included in the fusion construct. Error bars, S.E.