FIG. 5.

Measurement of fimA ON/OFF status in wild-type and ΔiscR strains. (A) Diagram showing the PCR fragment used to determine whether fimS (the fimA promoter) is in the ON or OFF state. Relative orientation of the HinfI restriction site and the fimA promoter are shown. Different fragments generated by HinfI digestion in both ON and OFF state are labeled. (B) Gel showing the relative abundance of ON and OFF fimS fragments in wild-type and ΔiscR strains. Quantification of ON fimS is shown below the gel (see Materials and Methods).