FIG. 5.
PqsE enhances C4-HSL activity in E. coli. E. coli strain DH5α carried either a vector plasmid (filled squares) or a plasmid harboring tacp-pqsE (open circles) and either a plasmid harboring tacp-rhlR and rhlA′-lacZ (A), a plasmid harboring tacp-rhlR and lasB′-lacZ (B), or a plasmid harboring tacp-lasR and lasB′-lacZ (C). Strains were cultured in the presence of exogenous signals as described in the Materials and Methods section, and β-Gal activity was measured. β-Gal activity is presented in Miller units as the mean ± SD of results from duplicate assays from at least three independent experiments.