Functional dissection of a conserved motif within the pilus retraction protein PilT.

ABSTRACT: PilT is a hexameric ATPase required for type IV pilus retraction in gram-negative bacteria. Retraction of type IV pili mediates intimate attachment to and signaling in host cells, surface motility, biofilm formation, natural transformation, and phage sensitivity. We investigated the in vivo and in vitro roles of each amino acid of the distinct, highly conserved C-terminal AIRNLIRE motif in PilT. Substitution of amino acids A288, I289, L292, and I293 as well as a double substitution of R290 and R294 abolished Pseudomonas aeruginosa PilT function in vivo, as measured by a loss of surface motility and phage sensitivity. When introduced into purified Aquifex aeolicus PilT, substitutions in the AIRNLIRE motif did not disrupt ATPase activity or oligomerization. In contrast, a K136Q substitution

SUBMITTER: Aukema KG 

PROVIDER: S-EPMC543540 | biostudies-literature | 2005 Jan

REPOSITORIES: biostudies-literature