Separation of Pseudomonas aeruginosa type IV pilus-dependent twitching motility and surface-sensing responses.

Many functions of Pseudomonas aeruginosa type IVa pili, including twitching motility and surface sensing, depend on dynamic cycles of filament assembly and disassembly powered by the cytoplasmic ATPases PilB, PilT, and PilU. Deletion of pilT results in loss of twitching and pilus-specific bacteriophage susceptibility, while non-twitching pilU mutants remain susceptible to pilus-specific phages, indicating that they still produce retractable …