We combined in vivo, in vitro, and in silico approaches to characterize the Pseudomonas aeruginosa T3SS needle and its major component PscF. Using a combination of mutagenesis, phenotypic analyses, immunofluorescence, proteolysis, mass spectrometry, atomic force microscopy, electron microscopy, and molecular modeling, we propose a model of the P. aeruginosa needle that exposes the N-terminal region of each PscF monomer toward the outside of the filament, while the core of the fiber is formed by the C-terminal helix.
AFM imaging was performed by Jean-Marie Teulon and TEM images were obtained by Daphna Fenel from samples provided by Viviana Job.
Lombardi C, Tolchard J, Bouillot S, Signor L, Gebus C, Liebl D, Fenel D, Teulon J-M, Brock J, Habenstein B, Pellequer J-L, Faudry E, Loquet A, Attrée I, Dessen A and Job V (2019) Structural and functional characterization of the Type Three Secretion System (T3SS) needle of Pseudomonas aeruginosa. Front. Microbiol. 10: 573.