VgrG, Tae, Tle, and beyond: the versatile arsenal of Type VI secretion effectors

Trends Microbiol. 2014 Sep;22(9):498-507. doi: 10.1016/j.tim.2014.06.004. Epub 2014 Jul 17.


The type VI secretion system (T6SS) is a macromolecular machine that delivers protein effectors into both prokaryotic and eukaryotic cells, therefore participating in interbacterial competition and virulence. The T6SS is functionally and structurally similar to the contractile bacteriophage cell puncturing device: the contraction of a sheath-like structure is believed to propel an inner tube terminated by a spike towards target cells, allowing the delivery of effectors. In this review, we summarize recent advances in the identification and characterization of T6SS effector proteins, highlighting the broad repertoire of enzymatic activities, and discuss recent findings relating to the secretion mechanisms.

Keywords: actin cross-linking; amidase; phospholipase; protein secretion; toxins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacterial Proteins / metabolism
  • Bacterial Proteins / physiology*
  • Bacterial Secretion Systems / physiology*
  • Bacteriophages / physiology
  • Bacteriophages / ultrastructure
  • Biological Transport
  • Microbial Interactions
  • Models, Molecular
  • Virulence
  • Virulence Factors / physiology*


  • Bacterial Proteins
  • Bacterial Secretion Systems
  • Virulence Factors