title: A view to a kill: the bacterial type VI secretion system.
abstract: The bacterial type VI secretion system (T6SS) is an organelle that is structurally and mechanistically analogous to an intracellular membrane-attached contractile phage tail. Recent studies determined that a rapid conformational change in the structure of a sheath protein complex propels T6SS spike and tube components along with antibacterial and antieukaryotic effectors out of predatory T6SS(+) cells and into prey cells. The contracted organelle is then recycled in an ATP-dependent process. T6SS is regulated at transcriptional and posttranslational levels, the latter involving detection of membrane perturbation in some species. In addition to directly targeting eukaryotic cells, the T6SS can also target other bacteria coinfecting a mammalian host, highlighting the importance of the T6SS not only for bacterial survival in environmental ecosystems, but also in the context of infection and disease. This review highlights these and other advances in our understanding of the structure, mechanical function, assembly, and regulation of the T6SS.
authors: Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
authors: Brian T
authors: BT
authors: Ho
authors: Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
authors: Tao G
authors: TG
authors: Dong
authors: Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA. Electronic address: john_mekalanos@hms.harvard.edu.
authors: John J
authors: JJ
authors: Mekalanos
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001419:Bacteria / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D058947:Bacterial Secretion Systems / Q000235:genetics*; D001435:Bacteriophages / Q000502:physiology / Q000648:ultrastructure; D005057:Eukaryotic Cells / Q000166:cytology / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D054884:Host-Pathogen Interactions; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053038:Quorum Sensing; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D008565:Membrane Proteins; D000255:Adenosine Triphosphate