Type VII secretion--mycobacteria show the way.
Recent evidence shows that mycobacteria have developed novel and specialized secretion systems for the transport of extracellular proteins across their hydrophobic, and highly impermeable, cell wall. Strikingly, mycobacterial genomes encode up to five of these transport systems. Two of these systems, ESX-1 and ESX-5, are involved in virulence - they both affect the cell-to-cell migration of pathogenic mycobacteria. Here, we discuss this novel secretion pathway and consider variants that are present in various Gram-positive bacteria. Given the unique composition of this secretion system, and its general importance, we propose that, in line with the accepted nomenclature, it should be called type VII secretion.
Abdallah
Abdallah M
AM
Department of Medical Microbiology, VU medical centre, Amsterdam 1081BT, The Netherlands.
Gey van Pittius
Nicolaas C
NC
Champion
Patricia A DiGiuseppe
PA
Cox
Jeffery
J
Luirink
Joen
J
Vandenbroucke-Grauls
Christina M J E
CM
Appelmelk
Ben J
BJ
Bitter
Wilbert
W
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009161:Mycobacterium / Q000378:metabolism*; D021381:Protein Transport; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins