| Pseudomonas aeruginosa 1244 is an opportunistic pathogen which displays fibrous appendages, called pili that are posttranslationally modified with a three sugar glycan. The gene responsible for pilin glycosylation, pilO, has been identified, but the exact role of the glycan has never been elucidated. A pilO− mutant was isolated in this study by a gene replacement technique resulting in the insertion of a gentamycin-resistance cassette into deletionally inactivated pilO gene. The pilO− mutant, P. aeruginosa 1244-G7, was shown to synthesize pili, as witnessed by TEM data and functionality was confirmed by the mutant's sensitivity to pilus-specific bacteriophage. The mutant displayed ∼26% less twitching motility than the wild type and a significant difference in adhesion to buccal epithelial cells was also noted. It is hypothesized that the difference in twitching motility may result from a pilus glycosylation state ‘preference’, involving adaptations of the pilus motor for glycosylated or non-glycosylated pilin. In addition, there are some data that indicates that the pilO − mutant produces fewer pili, which can also serve as an explanation for the twitching and adhesion defects. A possible role in proteolytic degradation protection is suggested for the glycan in this study, as well as other possible functions. |
