The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extension
Abstract The Tad (Tight adherence) 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...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2025-07-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-025-62457-8 |
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| author | Sasha L. Evans Iryna Peretiazhko Sahil Y. Karnani Lindsey S. Marmont James H. R. Wheeler Boo Shan Tseng William M. Durham John C. Whitney Julien R. C. Bergeron |
| author_facet | Sasha L. Evans Iryna Peretiazhko Sahil Y. Karnani Lindsey S. Marmont James H. R. Wheeler Boo Shan Tseng William M. Durham John C. Whitney Julien R. C. Bergeron |
| author_sort | Sasha L. Evans |
| collection | DOAJ |
| description | Abstract The Tad (Tight adherence) 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. |
| format | Article |
| id | doaj-art-ddc8b16a2ee24d7ba9c21b39a16e677e |
| institution | Kabale University |
| issn | 2041-1723 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj-art-ddc8b16a2ee24d7ba9c21b39a16e677e2025-08-20T03:42:55ZengNature PortfolioNature Communications2041-17232025-07-0116111110.1038/s41467-025-62457-8The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extensionSasha L. Evans0Iryna Peretiazhko1Sahil Y. Karnani2Lindsey S. Marmont3James H. R. Wheeler4Boo Shan Tseng5William M. Durham6John C. Whitney7Julien R. C. Bergeron8Randall Centre for Cell and Molecular Biophysics, King’s College LondonRandall Centre for Cell and Molecular Biophysics, King’s College LondonDepartment of Biochemistry and Biomedical Sciences, McMaster UniversityDepartment of Biochemistry and Biomedical Sciences, McMaster UniversitySchool of Mathematical and Physical Sciences, University of SheffieldSchool of Life Sciences, University of Nevada Las VegasSchool of Mathematical and Physical Sciences, University of SheffieldDepartment of Biochemistry and Biomedical Sciences, McMaster UniversityRandall Centre for Cell and Molecular Biophysics, King’s College LondonAbstract The Tad (Tight adherence) 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.https://doi.org/10.1038/s41467-025-62457-8 |
| spellingShingle | Sasha L. Evans Iryna Peretiazhko Sahil Y. Karnani Lindsey S. Marmont James H. R. Wheeler Boo Shan Tseng William M. Durham John C. Whitney Julien R. C. Bergeron The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extension Nature Communications |
| title | The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extension |
| title_full | The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extension |
| title_fullStr | The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extension |
| title_full_unstemmed | The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extension |
| title_short | The structure of the Tad pilus alignment complex reveals a periplasmic conduit for pilus extension |
| title_sort | structure of the tad pilus alignment complex reveals a periplasmic conduit for pilus extension |
| url | https://doi.org/10.1038/s41467-025-62457-8 |
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