Secretins: dynamic channels for protein transport across membranes

Trends Biochem Sci. 2011 Aug;36(8):433-43. doi: 10.1016/j.tibs.2011.04.002. Epub 2011 May 11.


Secretins form megadalton bacterial-membrane channels in at least four sophisticated multiprotein systems that are crucial for translocation of proteins and assembled fibers across the outer membrane of many species of bacteria. Secretin subunits contain multiple domains, which interact with numerous other proteins, including pilotins, secretion-system partner proteins, and exoproteins. Our understanding of the structure of secretins is rapidly progressing, and it is now recognized that features common to all secretins include a cylindrical arrangement of 12-15 subunits, a large periplasmic vestibule with a wide opening at one end and a periplasmic gate at the other. Secretins might also play a key role in the biogenesis of their cognate secretion systems.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacterial Outer Membrane Proteins / chemistry
  • Bacterial Outer Membrane Proteins / metabolism*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism
  • Gram-Negative Bacteria / chemistry
  • Gram-Negative Bacteria / metabolism
  • Membrane Transport Proteins / chemistry
  • Membrane Transport Proteins / metabolism*
  • Models, Molecular*
  • Protein Binding
  • Protein Conformation
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Protein Transport
  • Secretin / chemistry*
  • Secretin / physiology*


  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Carrier Proteins
  • Membrane Transport Proteins
  • Secretin