Type III machines of Gram-negative bacteria: delivering the goods

Trends Microbiol. 2000 May;8(5):214-20. doi: 10.1016/s0966-842x(99)01665-0.


Many Gram-negative pathogens use a type III secretion machine to translocate protein toxins across the bacterial cell envelope. Pathogenic Yersinia spp. export at least 14 Yop proteins via a type III machine, which recognizes secretion substrates by signals encoded in yop mRNA or chaperones bound to unfolded Yop proteins. During infection, substrate recognition appears to be regulated in a manner that allows the Yersinia type III pathway to direct Yops to the bacterial envelope, the extracellular medium or into the cytosol of host cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism*
  • Cells, Cultured
  • Eukaryotic Cells / microbiology
  • Gram-Negative Bacteria / metabolism*
  • Gram-Negative Bacteria / pathogenicity
  • Gram-Negative Bacterial Infections / microbiology
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism*
  • Signal Transduction
  • Yersinia / metabolism
  • Yersinia / pathogenicity


  • Bacterial Outer Membrane Proteins
  • Molecular Chaperones