Discovery of an Archetypal Protein Transport System in Bacterial Outer Membranes

Nat Struct Mol Biol. 2012 Apr 1;19(5):506-10, S1. doi: 10.1038/nsmb.2261.

Abstract

Bacteria have mechanisms to export proteins for diverse purposes, including colonization of hosts and pathogenesis. A small number of archetypal bacterial secretion machines have been found in several groups of bacteria and mediate a fundamentally distinct secretion process. Perhaps erroneously, proteins called 'autotransporters' have long been thought to be one of these protein secretion systems. Mounting evidence suggests that autotransporters might be substrates to be secreted, not an autonomous transporter system. We have discovered a new translocation and assembly module (TAM) that promotes efficient secretion of autotransporters in proteobacteria. Functional analysis of the TAM in Citrobacter rodentium, Salmonella enterica and Escherichia coli showed that it consists of an Omp85-family protein, TamA, in the outer membrane and TamB in the inner membrane of diverse bacterial species. The discovery of the TAM provides a new target for the development of therapies to inhibit colonization by bacterial pathogens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacterial Outer Membrane Proteins / analysis
  • Bacterial Outer Membrane Proteins / chemistry
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism*
  • Cell Line
  • Citrobacter rodentium / chemistry
  • Citrobacter rodentium / genetics
  • Citrobacter rodentium / metabolism*
  • Escherichia coli / chemistry
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / chemistry
  • Gene Deletion
  • Mice
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Transport*
  • Rabbits
  • Salmonella enterica / chemistry
  • Salmonella enterica / metabolism*

Substances

  • Bacterial Outer Membrane Proteins
  • BamA protein, E coli
  • Escherichia coli Proteins