title: Structure and specificity of the Type VI secretion system ClpV-TssC interaction in enteroaggregative Escherichia coli.
abstract: The Type VI secretion system (T6SS) is a versatile machine that delivers toxins into either eukaryotic or bacterial cells. It thus represents a key player in bacterial pathogenesis and inter-bacterial competition. Schematically, the T6SS can be viewed as a contractile tail structure anchored to the cell envelope. The contraction of the tail sheath propels the inner tube loaded with effectors towards the target cell. The components of the contracted tail sheath are then recycled by the ClpV AAA+ATPase for a new cycle of tail elongation. The T6SS is widespread in Gram-negative bacteria and most of their genomes carry several copies of T6SS gene clusters, which might be activated in different conditions. Here, we show that the ClpV ATPases encoded within the two T6SS gene clusters of enteroaggregative Escherichia coli are not interchangeable and specifically participate to the activity of their cognate T6SS. Here we show that this specificity is dictated by interaction between the ClpV N-terminal domains and the N-terminal helices of their cognate TssC1 proteins. We also present the crystal structure of the ClpV1 N-terminal domain, alone or in complex with the TssC1 N-terminal peptide, highlighting the commonalities and diversities in the recruitment of ClpV to contracted sheaths.
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques (AFMB, UMR 6098), Centre National de la Recherche Scientifique (CNRS), Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.|Architecture et Fonction des Macromolécules Biologiques (AFMB, UMR 6098), Aix-Marseille Univ, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.
authors.forename: Badreddine
authors.initials: B
authors.lastname: Douzi
authors.affiliation: Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Univ, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Yannick R
authors.initials: YR
authors.lastname: Brunet
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques (AFMB, UMR 6098), Centre National de la Recherche Scientifique (CNRS), Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.|Architecture et Fonction des Macromolécules Biologiques (AFMB, UMR 6098), Aix-Marseille Univ, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.
authors.forename: Silvia
authors.initials: S
authors.lastname: Spinelli
authors.affiliation: Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Univ, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Valentine
authors.initials: V
authors.lastname: Lensi
authors.affiliation: Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin - BP 48, 91192 Gif-sur-Yvette Cedex, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Legrand
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques (AFMB, UMR 6098), Centre National de la Recherche Scientifique (CNRS), Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.|Architecture et Fonction des Macromolécules Biologiques (AFMB, UMR 6098), Aix-Marseille Univ, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Blangy
authors.affiliation: Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Univ, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Anant
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Univ, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Journet
authors.affiliation: Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM, UMR 7255), Institut de Microbiologie de la Méditerranée (IMM), Centre National de la Recherche Scientifique (CNRS), Aix-Marseille Univ, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Cascales
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques (AFMB, UMR 6098), Centre National de la Recherche Scientifique (CNRS), Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.|Architecture et Fonction des Macromolécules Biologiques (AFMB, UMR 6098), Aix-Marseille Univ, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Cambillau
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D005810:Multigene Family; D000072417:Protein Domains; D000069376:Type VI Secretion Systems / Q000737:chemistry* / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D000069376:Type VI Secretion Systems; D000251:Adenosine Triphosphatases