title: Architecture and assembly of the Type VI secretion system.
abstract: The Type VI secretion system (T6SS) delivers protein effectors to diverse cell types including prokaryotic and eukaryotic cells, therefore it participates in inter-bacterial competition and pathogenesis. The T6SS is constituted of an envelope-spanning complex anchoring a cytoplasmic tubular edifice. This tubular structure is evolutionarily, functionally and structurally related to the tail of contractile phages. It is composed of an inner tube tipped by a spike complex, and engulfed within a sheath-like structure. This structure assembles onto a platform called "baseplate" that is connected to the membrane sub-complex. The T6SS functions as a nano-crossbow: upon contraction of the sheath, the inner tube is propelled towards the target cell, allowing effector delivery. This review focuses on the architecture and biogenesis of this fascinating secretion machine, highlighting recent advances regarding the assembly of the membrane or tail complexes. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
authors.affiliation: Laboratoire d'Ingeniérie des Systèmes Macromoléculaires, CNRS, Aix-Marseille Université, UMR 7255, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Abdelrahim
authors.initials: A
authors.lastname: Zoued
authors.affiliation: Laboratoire d'Ingeniérie des Systèmes Macromoléculaires, CNRS, Aix-Marseille Université, UMR 7255, 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, CNRS, Aix-Marseille Université, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Durand
authors.affiliation: Laboratoire d'Ingeniérie des Systèmes Macromoléculaires, CNRS, Aix-Marseille Université, UMR 7255, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Marie-Stéphanie
authors.initials: MS
authors.lastname: Aschtgen
authors.affiliation: Laboratoire d'Ingeniérie des Systèmes Macromoléculaires, CNRS, Aix-Marseille Université, UMR 7255, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Laureen
authors.initials: L
authors.lastname: Logger
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.
authors.forename: Badreddine
authors.initials: B
authors.lastname: Douzi
authors.affiliation: Laboratoire d'Ingeniérie des Systèmes Macromoléculaires, CNRS, Aix-Marseille Université, UMR 7255, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Journet
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Cambillau
authors.affiliation: Laboratoire d'Ingeniérie des Systèmes Macromoléculaires, CNRS, Aix-Marseille Université, UMR 7255, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. Electronic address: cascales@imm.cnrs.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Cascales
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000472:pathogenicity*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D058947:Bacterial Secretion Systems / Q000235:genetics*; D001435:Bacteriophages / Q000737:chemistry / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005057:Eukaryotic Cells / Q000378:metabolism; D011387:Prokaryotic Cells / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems
keywords: Assembly platform; Bacteriophage; Baseplate; Hcp; Inter-bacterial interactions; Membrane complex; Microbial communities; Protein transport; Secretion system; Tail; VgrG