Function and molecular architecture of the Yersinia injectisome tip complex

• Published in: Molecular microbiology 2007-09, Vol.65 (5), p.1311-1320
• Main Authors: Broz, Petr, Mueller, Catherine A., Müller, Shirley A., Philippsen, Ansgar, Sorg, Isabel, Engel, Andreas, Cornelis, Guy R.
• Format: Article
• Language: English
• Subjects: Aeromonas salmonicida; Antigens, Bacterial - chemistry; Antigens, Bacterial - genetics; Antigens, Bacterial - metabolism; Bacteria; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Biological and medical sciences; Cells; Fundamental and applied biological sciences. Psychology; Gene expression; Membranes; Microbiology; Miscellaneous; Models, Molecular; Molecular structure; Multiprotein Complexes; Pore Forming Cytotoxic Proteins - chemistry; Pore Forming Cytotoxic Proteins - genetics; Pore Forming Cytotoxic Proteins - metabolism; Protein Structure, Quaternary; Protein Subunits - chemistry; Protein Subunits - genetics; Protein Subunits - metabolism; Pseudomonas aeruginosa; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Transmission electron microscopy; Yersinia enterocolitica; Yersinia enterocolitica - pathogenicity; Yersinia enterocolitica - ultrastructure; Yersinia Infections - metabolism
• ISSN: 0950-382X; 1365-2958
• DOI: 10.1111/j.1365-2958.2007.05871.x

Summary By quantitative immunoblot analyses and scanning transmission electron microscopy (STEM), we determined that the needle of the Yersinia enterocolitica E40 injectisome consists of 139 ± 19 YscF subunits and that the tip complex is formed by three to five LcrV monomers. A pentamer represented the best fit for an atomic model of this complex. The N‐terminal globular domain of LcrV forms the base of the tip complex, while the central globular domain forms the head. Hybrids between LcrV and its orthologues PcrV (Pseudomonas aeruginosa) or AcrV (Aeromonas salmonicida) were engineered and recombinant Y. enterocolitica expressing the different hybrids were tested for their capacity to form the translocation pore by a haemolysis assay. There was a good correlation between haemolysis, insertion of YopB into erythrocyte membranes and interaction between YopB and the N‐terminal globular domain of the tip complex subunit. Hence, the base of the tip complex appears to be critical for the functional insertion of YopB into the host cell membrane.