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Cited by 8Biochemical and Structural CharacterizationAdvanced Electron Microscopy Techniques and ApplicationsBacterial Genetics and Biotechnology

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The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extension

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Evans, Sasha L., Peretiazhko, Iryna, Karnani, Sahil Y., Marmont, Lindsey S., Wheeler, James H. R., Tseng, Boo Shan, Durham, William M., Whitney, John C., Bergeron, Julien R. C.·2025·Nature Communications
DOI 10.1038/s41467-025-62457-8PMC PMC12307814

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Abstract

The Tad ( T ight ad herence) pilus is a bacterial appendage implicated in virulence, cell-cell aggregation, and biofilm formation. Despite its homology to the well-characterised Type IV pilus, the structure and assembly mechanism of the Tad pilus are poorly understood. Here, we investigate the role of the Tad pilus protein RcpC from Pseudomonas aeruginosa . Our analyses reveal that RcpC forms a dodecameric periplasmic complex, anchored to the inner membrane by a transmembrane helix, and interacting with the outer membrane secretin RcpA. We use single-particle Cryo-EM to elucidate the structure of the RcpC dodecamer, and cell-based assays to demonstrate that the RcpC-RcpA complex is essential for Tad-mediated cell-cell aggregation. Collectively, these data demonstrate that RcpC forms the Tad pilus alignment complex, which provides a conduit across the periplasm for the Tad pilus filament to access the extracellular milieu. Our experimental data and structure-based model allow us to propose a mechanism for Tad plus assembly.

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Metadata

Authors
Evans, S. L., Peretiazhko, I., Karnani, S. Y., Marmont, L. S., Wheeler, J. H. R., Tseng, B. S., Durham, W. M., Whitney, J. C., & Bergeron, J. R. C.
Affiliations
  • King's College London (GB)
  • University of Toronto (CA)
  • McMaster University (CA)
  • University of Liverpool (GB)
  • University of Nevada, Las Vegas (US)
  • University of Sheffield (GB)
Corresponding author
  • Evans, Sasha L.
  • Bergeron, Julien R. C.
ORCID
Venue
Nature Communications
Publisher
Springer Science and Business Media LLC
Published
2025-07-29
Volume
16
Issue
1
Pages
6977-6977
ISSN
2041-1723 (ISSN-L)
DOI
10.1038/s41467-025-62457-8
PMC
PMC12307814
OpenAlex
W4412785590
Cited by
8
References
2
Citations by year
2026: 4 · 2025: 4
FWCI
2.37
Type
journal article
Language
en
Open access
Licence
Locations
  • Nature Communications (publishedVersion, cc-by)
  • bioRxiv (Cold Spring Harbor Laboratory) (acceptedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • White Rose Research Online (University of Leeds, The University of Sheffield, University of York) (acceptedVersion)
  • Research Portal (King's College London) (submittedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
  • Human Frontier Science Program (RGY0080/2021)
  • RCUK | Biotechnology and Biological Sciences Research Council (BB/V019732/1, BB/T01752X/1)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Biochemical and Structural Characterization
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Structural Biology › Advanced Electron Microscopy Techniques and Applications
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Bacterial Genetics and Biotechnology
Keywords
Tad pilus, Pseudomonas aeruginosa, type IV pili, cell-cell aggregation, biofilm formation, virulence, transmembrane helices
MeSH terms
Bacterial Adhesion, Bacterial Proteins, Models, Molecular, Fimbriae, Bacterial, Pseudomonas aeruginosa, Periplasm, Cryoelectron Microscopy, Fimbriae Proteins

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