Type IVB secretion by intracellular pathogens

Traffic. 2002 Mar;3(3):178-85. doi: 10.1034/j.1600-0854.2002.030303.x.


A growing number of pathogens are being found to possess specialized secretion systems which they use in various ways to subvert host defenses. One class, called type IV, are defined as having homology to the conjugal transfer systems of naturally occurring plasmids. It has been proposed that pathogens with type IV secretion systems have acquired and adapted the conjugal transfer systems of plasmids and now use them to export toxins. Several well-characterized intracellular pathogens, including Legionella pneumophila, Coxiella burnetii, Brucella abortus, and Rickettsia prowazekii, contain type IV systems which are known or suspected to be of critical importance in their ability to cause disease. Specifically, these systems are believed to be the key factors determining intracellular fate, and thus the ability to replicate and cause disease.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / metabolism
  • Bacterial Proteins / physiology*
  • Brucella abortus / pathogenicity
  • Coxiella burnetii / pathogenicity
  • Legionella pneumophila / pathogenicity
  • Molecular Sequence Data
  • Phagocytosis
  • Pseudomonas / pathogenicity
  • Rickettsia prowazekii / pathogenicity
  • Sequence Homology, Amino Acid
  • Virulence Factors*


  • Bacterial Proteins
  • Virulence Factors