FIG 3 .

RcsB controls secretion of Hcp. Filtered supernatants from saturated cultures of the indicated S. marcescens RM66262 strains were precipitated and loaded into 15% SDS-PAGE gels. Hcp levels were determined by immunodetection using Hcp antisera followed by densitometry. (Top) Representative image of the assay. (Bottom) Average values ± standard deviations (SD) from three independent experiments are shown (**, P < 0.01; ***, P < 0.001). See Fig. S2 in the supplemental material for the densitometry normalization procedure employed.