A view to a kill: the bacterial type VI secretion system

Cell Host Microbe. 2014 Jan 15;15(1):9-21. doi: 10.1016/j.chom.2013.11.008. Epub 2013 Dec 11.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Bacteria / genetics
  • Bacteria / metabolism*
  • Bacteria / pathogenicity
  • Bacteria / ultrastructure
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Bacterial Secretion Systems / genetics*
  • Bacteriophages / physiology
  • Bacteriophages / ultrastructure
  • Eukaryotic Cells / cytology
  • Eukaryotic Cells / microbiology
  • Gene Expression Regulation, Bacterial*
  • Host-Pathogen Interactions
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Quorum Sensing
  • Signal Transduction


  • Bacterial Proteins
  • Bacterial Secretion Systems
  • Membrane Proteins
  • Adenosine Triphosphate