1. Microbiology and Infectious Disease
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Structural basis of host recognition and biofilm formation by Salmonella Saf pili

  1. Longhui Zeng
  2. Li Zhang
  3. Pengran Wang
  4. Guoyu Meng  Is a corresponding author
  1. Shanghai JiaoTong University, China
Research Article
  • Cited 7
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Cite this article as: eLife 2017;6:e28619 doi: 10.7554/eLife.28619

Abstract

Pili are critical in host recognition, colonization and biofilm formation during bacterial infection. Here, we report the crystal structures of SafD-dsc and SafD-SafA-SafA (SafDAA-dsc) in Saf pili. Cell adherence assays show that SafD and SafA are both required for host recognition, suggesting a poly-adhesive mechanism for Saf pili. Moreover, the SafDAA-dsc structure, as well as SAXS characterization, reveals an unexpected inter-molecular oligomerization, prompting the investigation of Saf-driven self-association in biofilm formation. The bead/cell aggregation and biofilm formation assays are used to demonstrate the novel function of Saf pili. Structure-based mutants targeting the inter-molecular hydrogen bonds and complementary architecture/surfaces in SafDAA-dsc dimers significantly impaired the Saf self-association activity and biofilm formation. In summary, our results identify two novel functions of Saf pili: the poly-adhesive and self-associating activities. More importantly, Saf-Saf structures and functional characterizations help to define a pili-mediated inter-cellular oligomerizaiton mechanism for bacterial aggregation, colonization and ultimate biofilm formation.

Article and author information

Author details

  1. Longhui Zeng

    State Key Laboratory of Medical Genomics, Shanghai JiaoTong University, Shanghai, China
    Competing interests
    The authors declare that no competing interests exist.
  2. Li Zhang

    State Key Laboratory of Medical Genomics, Shanghai JiaoTong University, Shanghai, China
    Competing interests
    The authors declare that no competing interests exist.
  3. Pengran Wang

    State Key Laboratory of Medical Genomics, Shanghai JiaoTong University, Shanghai, China
    Competing interests
    The authors declare that no competing interests exist.
  4. Guoyu Meng

    State Key Laboratory of Medical Genomics, Shanghai JiaoTong University, Shanghai, China
    For correspondence
    guoyumeng@shsmu.edu.cn
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7904-2382

Funding

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

Reviewing Editor

  1. Scott Hultgren, Washington University in St. Louis, United States

Publication history

  1. Received: May 14, 2017
  2. Accepted: November 8, 2017
  3. Accepted Manuscript published: November 10, 2017 (version 1)
  4. Version of Record published: November 23, 2017 (version 2)
  5. Version of Record updated: November 30, 2017 (version 3)

Copyright

© 2017, Zeng 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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