The ins and outs of Mycobacterium tuberculosis protein export

Tuberculosis (Edinb). 2012 Mar;92(2):121-32. doi: 10.1016/ Epub 2011 Dec 21.


Mycobacterium tuberculosis is an important pathogen that infects approximately one-third of the world's population and kills almost two million people annually. An important aspect of M. tuberculosis physiology and pathogenesis is its ability to export proteins into and across the thick mycobacterial cell envelope, where they are ideally positioned to interact with the host. In addition to the specific proteins that are exported by M. tuberculosis, the systems through which these proteins are exported represent potential targets for future drug development. M. tuberculosis possesses two well-known and conserved export systems: the housekeeping Sec pathway and the Tat pathway. In addition, M. tuberculosis possesses specialized export systems including the accessory SecA2 pathway and five ESX pathways. Here we review the current understanding of each of these export systems, with a focus on M. tuberculosis, and discuss the contribution of each system to disease and physiology.

Publication types

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

MeSH terms

  • Adenosine Triphosphatases / physiology
  • Bacterial Proteins / metabolism*
  • Bacterial Proteins / physiology
  • Cell Membrane / metabolism
  • Host-Pathogen Interactions / physiology
  • Humans
  • Membrane Transport Proteins / physiology
  • Models, Biological
  • Mycobacterium tuberculosis / metabolism*
  • Protein Transport / physiology


  • Bacterial Proteins
  • Membrane Transport Proteins
  • Adenosine Triphosphatases
  • SecA2 protein, Mycobacterium