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Updated: Aug 20, 2025
11:33
Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
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Structural Model of a Porphyromonas gingivalis type IX Secretion System Shuttle Complex
Ben Dorgan1, Yichao Liu2, Sunjun Wang2
1Centre for Host-Microbiome Interactions, Faculty of Dental, Oral & Craniofacial Sciences, King's College London, London, UK; School of Biological and Chemical Sciences, Queen Mary University of London, London, UK.
Journal of Molecular Biology
|November 21, 2022
Summary
Porphyromonas gingivalis uses the type IX secretion system (T9SS) to export virulence factors like RgpB. Researchers structurally modeled the interaction between PorV and RgpB
Area of Science:
- Microbiology
- Structural Biology
- Biochemistry
Background:
- Porphyromonas gingivalis is a key pathogen in periodontitis.
- Virulence factors are exported via the type IX secretion system (T9SS).
- Cargo proteins require a C-terminal domain (CTD) for T9SS recognition.
Purpose of the Study:
- To elucidate the structural mechanism of CTD recognition by the T9SS.
- To present a structural model of the PorV:RgpB-CTD complex.
Main Methods:
- Solution nuclear magnetic resonance (NMR) spectroscopy
- Biochemical analyses
- Machine-learning-based modeling
- Molecular dynamics (MD) simulations
Main Results:
- A structural model of the PorV:RgpB-CTD complex was determined.
- Conserved motifs in the CTD are critical for binding to PorV.
- Extracellular loops of PorV mediate CTD binding, cradling the cargo.
Conclusions:
- This study provides the first structural insight into CTD recognition by the T9SS.
- Understanding PorV-CTD interaction is crucial for P. gingivalis pathogenesis.
- Findings may inform broader understanding of type IX secretion.
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