tailieunhanh - Báo cáo khoa học: Architecture of the Helicobacter pylori Cag-type IV secretion system

Type IV secretion systems (T4SS) are macromolecular assemblies used by bacteria to transport material across their membranes. T4SS are generally composed of a set of twelve proteins (VirB1–11 and VirD4). This repre-sents a dynamic machine powered by three ATPases. | IFEBS Journal MINIREVIEW Architecture of the Helicobacter pylori Cag-type IV secretion system Laurent Terradot1 and Gabriel Waksman2 1 Institut de Biologie et Chimie des Proteines Biologie Structurale des Complexes Macromoleculaires Bacteriens UMR 5086 CNRS Universite de Lyon France 2 Institute of Structuraland Molecular Biology UCL and Birkbeck London UK Keywords bacterialpathogenesis CagA secretion system stomach cancer translocation Correspondence L. Terradot Institut de Biologie et Chimie des Proteines Biologie Structurale des Complexes Macromoleculaires Bacteriens UMR 5086 CNRS Universite de Lyon IFR128 7 Passage du Vercors F-69367 Lyon Cedex 07 France Fax 33 472 722604 Tel 33 472 722652 E-mail and G. Waksman Institute of Structuraland Molecular Biology UCL and Birkbeck Malet Street London WC1E 7HX UK Fax 44 0 207 631 6803 Tel 44 0 207 631 6833 E-mail or Received 15 November 2010 revised 18 January 2011 accepted 27 January 2011 doi Type IV secretion systems T4SS are macromolecular assemblies used by bacteria to transport material across their membranes. T4SS are generally composed of a set of twelve proteins VirB1-11 and VirD4 . This represents a dynamic machine powered by three ATPases. T4SS are widespread in pathogenic bacteria where they are often used to deliver effectors into host cells. For example the human pathogen Helicobacter pylori encodes a T4SS the Cag-T4SS which mediates the injection of the toxin CagA. We review the progress made in the past decade in our understanding of T4SS architecture. We translate this new knowledge to derive an understanding of the structure of the H. pylori Cag system and use recent protein-protein interaction data to refine this model. Introduction Secretion systems are widespread in bacteria for which they provide means of exchange between the extra-and intracellular milieus. Seven different systems have been described in