@article{198976,
  keywords = {Bacterial Adhesion, Escherichia coli, Colony Count, Microbial, Gene Deletion, Escherichia coli Proteins, Bacterial Outer Membrane Proteins, Mutation, Missense, Microbial Viability, Multidrug Resistance-Associated Proteins},
  author = {Stephanie Aoki and Juliana Malinverni and Kyle Jacoby and Benjamin Thomas and Rupinderjit Pamma and Brooke Trinh and Susan Remers and Julia Webb and Bruce Braaten and Thomas Silhavy and David Low},
  title = {Contact-dependent growth inhibition requires the essential outer membrane protein BamA (YaeT) as the receptor and the inner membrane transport protein AcrB},
  abstract = {<p>Contact-dependent growth inhibition (CDI) is a phenomenon by which bacterial cell growth is regulated by direct cell-to-cell contact via the CdiA/CdiB two-partner secretion system. Characterization of mutants resistant to CDI allowed us to identify BamA (YaeT) as the outer membrane receptor for CDI and AcrB as a potential downstream target. Notably, both BamA and AcrB are part of distinct multi-component machines. The Bam machine assembles outer membrane beta-barrel proteins into the outer membrane and the Acr machine exports small molecules into the extracellular milieu. We discovered that a mutation that reduces expression of BamA decreased binding of CDI+ inhibitor cells, measured by flow cytometry with fluorescently labelled bacteria. In addition, alpha-BamA antibodies, which recognized extracellular epitopes of BamA based on immunofluorescence, specifically blocked inhibitor-target cells binding and CDI. A second class of CDI-resistant mutants identified carried null mutations in the acrB gene. AcrB is an inner membrane component of a multidrug efflux pump that normally forms a cell envelope-spanning complex with the membrane fusion protein AcrA and the outer membrane protein TolC. Strikingly, the requirement for the BamA and AcrB proteins in CDI is independent of their multi-component machines, and thus their role in the CDI pathway may reflect novel, import-related functions.</p>
},
  year = {2008},
  journal = {Mol Microbiol},
  volume = {70},
  pages = {323-40},
  month = {10/2008},
  issn = {1365-2958},
  doi = {10.1111/j.1365-2958.2008.06404.x},
  language = {eng},
}