title: Take five - Type VII secretion systems of Mycobacteria.
abstract: Mycobacteria use type VII secretion (T7S) systems to secrete proteins across their complex cell envelope. Pathogenic mycobacteria, such as the notorious pathogen Mycobacterium tuberculosis, have up to five of these secretion systems, named ESX-1 to ESX-5. At least three of these secretion systems are essential for mycobacterial virulence and/or viability. Elucidating T7S is therefore essential to understand the success of M. tuberculosis and other pathogenic mycobacteria as pathogens, and could be instrumental to identify novel targets for drug- and vaccine-development. Recently, significant progress has been achieved in the identification of T7S substrates and a general secretion motif. In addition, a start has been made with unraveling the mechanism of secretion and the structural analysis of the different subunits. This review summarizes these recent findings, which are incorporated in a working model of this complex machinery. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
authors.affiliation: VU University, Amsterdam, The Netherlands; VU University Medical Center, Amsterdam, The Netherlands. Electronic address: e.n.g.houben@vu.nl.
authors.forename: Edith N G
authors.initials: EN
authors.lastname: Houben
authors.affiliation: University of Kentucky, Lexington, KY, USA.
authors.forename: Konstantin V
authors.initials: KV
authors.lastname: Korotkov
authors.affiliation: VU University, Amsterdam, The Netherlands; VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Wilbert
authors.initials: W
authors.lastname: Bitter
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D058947:Bacterial Secretion Systems / Q000235:genetics*; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D006801:Humans; D018832:Molecular Chaperones / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000737:chemistry / Q000378:metabolism / Q000472:pathogenicity*; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000235:genetics*; D014376:Tuberculosis / Q000235:genetics / Q000378:metabolism / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D018832:Molecular Chaperones
keywords: Chaperone; Mycobacterium; Protease; Protein secretion; Secretion signal