FIG. 4.

Regulatory influence of fimYZ on hilA-lacZY expression. Deletion of fimZ increased hilA-lacZY expression, while overexpression of fimYZ within S. enterica serovar Typhimurium repressed an hilA-lacZY reporter. A deletion of the hilE gene eliminated the effect of fimYZ overexpression on hilA expression. Cultures were grown to the late stationary phase in Lennox broth. Levels of lacZ activity were measured by the β-galactosidase assay. Each assay was performed in triplicate and repeated three times.