Article Title: High-resolution view of the type III secretion export apparatus in situ reveals membrane remodeling and a secretion pathway
Figure Lengend Snippet: Interaction of the periplasmic PrgK ring with the export apparatus is required for type III secretion function but not for injectisome assembly. (A - F) Top view ( A ) and cross section ( D ) of the 3D reconstruction of the IR1 and IR2 rings of the needle complex containing the core components of the export apparatus. The interface between PrgK and the export apparatus is highlighted (in blue and red rectangles). The specific densities corresponding to PrgK residues 93-96 targeted for mutagenesis and functional analysis are shown in more detailed in the zoom-in views depicted in panels B through F . ( G ) Representative class averages of needle complexes isolated from S. Typhimurium expressing wild type PrgK or the indicated deletion mutants. ( H ) Type III protein secretion analysis of S. Typhimurium strains expressing the PrgK mutants with the indicated deletions in the region that interacts with the core components of the export apparatus. Whole cell lysates and cultured supernatants of the indicated strains were analyzed by Western immunoblot for the presence of SipB, SipC, and InvJ, which are substrates of the S. Typhimurium type III secretion system.
Article Snippet: Typhimurium strains as indicated above.
Techniques: Mutagenesis, Functional Assay, Isolation, Expressing, Cell Culture, Western Blot