FIG. 10.

VpsS negatively regulates protease activity. Protease activity in wild-type (Wt), ΔluxU, ΔluxO, ΔhapR, and ΔluxO ΔhapR strains harboring the vector (open bars) or pvpsS (filled bars) was examined. Strains were grown in LB medium supplemented with ampicillin and 0.2% arabinose to induce vpsS expression. The results are expressed in arbitrary units of fluorescence measured at 530 nm normalized to cell density (OD₆₀₀). The error bars indicate standard deviations of three technical replicates. The results of one representative experiment of four biological replicates are shown.