Contact-dependent killing by Caulobacter crescentus via cell surface-associated, glycine zipper proteins

  1. Leonor Garcia-Bayona
  2. Monica S Guo
  3. Michael T Laub  Is a corresponding author
  1. Massachusetts Institute of Technology, United States

Abstract

Most bacteria are in fierce competition with other species for limited nutrients. Some bacteria can kill nearby cells by secreting bacteriocins, a diverse group of proteinaceous antimicrobials. However, bacteriocins are typically freely diffusible, and so of little value to planktonic cells in aqueous environments. Here, we identify an atypical two-protein bacteriocin in the α-proteobacterium Caulobacter crescentus that is retained on the surface of producer cells where it mediates cell contact-dependent killing. The bacteriocin-like proteins CdzC and CdzD harbor glycine-zipper motifs, often found in amyloids, and CdzC forms large, insoluble aggregates on the surface of producer cells. These aggregates can drive contact-dependent killing of other organisms, or Caulobacter cells not producing the CdzI immunity protein. The Cdz system uses a type I secretion system and is unrelated to previously described contact-dependent inhibition systems. However, Cdz-like systems are found in many bacteria, suggesting that this form of contact-dependent inhibition is common.

Article and author information

Author details

  1. Leonor Garcia-Bayona

    Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
    Competing interests
    No competing interests declared.
  2. Monica S Guo

    Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
    Competing interests
    No competing interests declared.
  3. Michael T Laub

    Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
    For correspondence
    laub@mit.edu
    Competing interests
    Michael T Laub, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8288-7607

Funding

National Institutes of Health (R01GM082899)

  • Michael T Laub

Howard Hughes Medical Institute

  • Leonor Garcia-Bayona
  • Michael T Laub

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Tâm Mignot, Aix Marseille University-CNRS UMR7283, France

Version history

  1. Received: January 3, 2017
  2. Accepted: March 20, 2017
  3. Accepted Manuscript published: March 21, 2017 (version 1)
  4. Version of Record published: April 4, 2017 (version 2)

Copyright

© 2017, Garcia-Bayona et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Leonor Garcia-Bayona
  2. Monica S Guo
  3. Michael T Laub
(2017)
Contact-dependent killing by Caulobacter crescentus via cell surface-associated, glycine zipper proteins
eLife 6:e24869.
https://doi.org/10.7554/eLife.24869

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https://doi.org/10.7554/eLife.24869

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