FIG. 3.

Functional characterization of the pilF::Tn5 mutant. Characterization of T4P expression and function of wild-type P. aeruginosa strain mPAO1, the pilF::Tn5 mutant, the pilF::Tn5 mutant complemented with PilF (+F), and the C18G lipidation mutant. (A) Representative plates showing twitching motility movement of cells away from the point of inoculation detected by using crystal violet dye. Bar, 1 cm. (B) Average twitching zone areas quantified from at least 23 replicates. All values are significantly different from each other at a P value of <0.0001. Error bars show standard deviations. (C) Sheared surface proteins were analyzed by Coomassie-stained 16% SDS-PAGE. The positions of the pilin and flagellin bands are indicated. Values at the bottom represent the ratio of pilin relative to the level in mPAO1 after normalization to the amount of flagellin present. The molecular mass ladder (top to bottom) is 130, 100, 70, 55, 45, 35, 25, 15, and 10 kDa. (D) The strains were tested for sensitivity to PO4 bacteriophage lysis. Sensitivity was defined as the absence of growth on contact with PO4 phage that had been spotted on the center of the plate.