Towards a complete structural deciphering of Type VI secretion system

Curr Opin Struct Biol. 2018 Apr;49:77-84. doi: 10.1016/ Epub 2018 Feb 2.


The Type VI secretion system (T6SS) is a dynamic nanomachine present in many Gram-negative bacteria. Using a contraction mechanism similar to that of myophages, bacteriocins or anti-feeding prophages, it injects toxic effectors into both eukaryotic and prokaryotic cells. T6SS assembles three large ensembles: the trans-membrane complex (TMC), the baseplate and the tail. Recently, the tail structure has been elucidated by cryo electron microscopy (cryoEM) in extended and contracted forms. The structure of the trans-membrane complex has been deciphered using a combination of X-ray crystallography and EM. However, the structural characterisation of the baseplate lags behind and should be the target of future studies. Finally, cryo-tomography should provide low/medium resolution maps allowing to assemble the different parts ultimately leading to a complete structural description of T6SS.

Publication types

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

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / ultrastructure
  • Cryoelectron Microscopy
  • Crystallography, X-Ray
  • Gram-Negative Bacteria / chemistry*
  • Gram-Negative Bacteria / ultrastructure
  • Models, Molecular
  • Protein Conformation
  • Type VI Secretion Systems / chemistry*
  • Type VI Secretion Systems / ultrastructure


  • Bacterial Proteins
  • Type VI Secretion Systems