Open AccessThe Pseudomonas aeruginosa Ribbon-Helix-Helix DNA-Binding Protein AlgZ (AmrZ) Controls Twitching Motility and Biogenesis of Type IV Pili
Author(s) -
Patricia J. Baynham,
Deborah M. Ramsey,
Borys V. Gvozdyev,
Ellen M. Cordonnier,
Daniel J. Wozniak
Publication year - 2005
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.188.1.132-140.2006
Subject(s) - pilus , pilin , biology , pseudomonas aeruginosa , motility , flagellum , microbiology and biotechnology , biogenesis , mutant , operon , biofilm , fimbriae proteins , biochemistry , bacteria , escherichia coli , gene , genetics
Pseudomonas aeruginosa is an opportunistic pathogen that is commonly found in water and soil. In order to colonize surfaces with low water content,P. aeruginosa utilizes a flagellum-independent form of locomotion called twitching motility, which is dependent upon the extension and retraction of type IV pili. This study demonstrates that AlgZ, previously identified as a DNA-binding protein absolutely required for transcription of the alginate biosynthetic operon, is required for twitching motility. AlgZ may be required for the biogenesis or function of type IV pili in twitching motility. Transmission electron microscopy analysis of analgZ deletion in nonmucoid PAO1 failed to detect surface pili. To examine expression and localization of PilA (the major pilin subunit), whole-cell extracts and cell surface pilin preparations were analyzed by Western blotting. While the PilA levels present in whole-cell extracts were similar for wild-typeP. aeruginosa andP. aeruginosa with thealgZ deletion, the amount of PilA on the surface of the cells was drastically reduced in thealgZ mutant. Analysis ofalgZ andalgD mutants indicates that the DNA-binding activity of AlgZ is essential for the regulation of twitching motility and that this is independent of the role of AlgZ in alginate expression. These data show that AlgZ DNA-binding activity is required for twitching motility independently of its role in alginate production and that this involves the surface localization of type IV pili. Given this new role in twitching motility, we propose thatalgZ (PA3385) be designatedamrZ (a lginate andm otilityr egulatorZ ).