1. Atomic force and super-resolution microscopy support a role for LapA as a cell-surface biofilm adhesin of Pseudomonas fluorescens
- Author
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Ivanov, IE, Boyd, CD, Newell, PD, Schwartz, ME, Turnbull, L, Johnson, MS, Whitchurch, CB, O'Toole, GA, Camesano, TA, Ivanov, IE, Boyd, CD, Newell, PD, Schwartz, ME, Turnbull, L, Johnson, MS, Whitchurch, CB, O'Toole, GA, and Camesano, TA
- Abstract
Pseudomonas fluorescence Pf0-1 requires the large repeat protein LapA for stable surface attachment. This study presents direct evidence that LapA is a cell-surface-localized adhesin. Atomic force microscopy (AFM) revealed a significant 2-fold reduction in adhesion force for mutants lacking the LapA protein on the cell surface compared to the wild-type strain. Deletion of lapG, a gene encoding a periplasmic cysteine protease that functions to release LapA from the cell surface, resulted in a 2-fold increase in the force of adhesion. Three-dimensional structured illumination microscopy (3D-SIM) revealed the presence of the LapA protein on the cell surface, consistent with its role as an adhesin. The protein is only visualized in the cytoplasm for a mutant of the ABC transporter responsible for translocating LapA to the cell surface. Together, these data highlight the power of combining the use of AFM and 3D-SIM with genetic studies to demonstrate that LapA, a member of a large group of RTX-like repeat proteins, is a cell-surface adhesin. © 2012 Institut Pasteur.
- Published
- 2012