ArticlePLoS pathogens2016
Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.
Article in PLoS pathogens, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 51 papers.
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Who cites it
51 citing papers in PubMed, 91 citations in OpenAlex.
- OmpA_C-Like Domain of PorE Is Essential for PorE Function in the Type IX Secretion System (T9SS) of Porphyromonas gingivalis and Some T9SS Cargo Proteins Are Secreted in a PorE-Independent Manner.Microbiology and immunology · 2026Article
- A shared mechanism for Bacteroidota protein transport and gliding motility.Nature communications · 2025Article
- Specialized shuttle proteins recognize Type IX secretion signals and target effectors to their final destinations in Flavobacterium johnsoniae.Communications biology · 2025Article
- Article
- Insights into type IX secretion from PorKN cogwheel structure bound to PorG and attachment complexes.Nature communications · 2025Article
- Structural studies of ribosome from an anaerobic Bacteroidetes human pathogen Porphyromonas gingivalis.Nucleic acids research · 2025Article
- LolA and LolB are conserved in Bacteroidota and are crucial for gliding motility and Type IX secretion.Communications biology · 2025Article
- TheJournal of oral microbiology · 2025Article
- Advances in the type IX secretion system: an exploration focusing onCurrent research in microbial sciences · 2025Review
- Structural insights into the mechanism of protein transport by the Type 9 Secretion System translocon.Nature microbiology · 2024Article
- Structure-function analysis of PorXScientific reports · 2024Article
- A journey with type IX secretion system effectors: selection, transport, processing and activities.Microbiology (Reading, England) · 2023Article
- Protein interactome mapping of Porphyromonas gingivalis provides insights into the formation of the PorQ-Z complex of the type IX secretion system.Molecular oral microbiology · 2023Article
- Filamentous structures in the cell envelope are associated with bacteroidetes gliding machinery.Communications biology · 2023Article
- Live Cell Imaging of Gliding Motility of Flavobacterium johnsoniae Under High-Resolution Microscopy.Methods in molecular biology (Clifton, N.J.) · 2023Article
- Research Progress on Small Molecular Inhibitors of the Type 3 Secretion System.Molecules (Basel, Switzerland) · 2022Review
- The type IX secretion system: Insights into its function and connection to glycosylation inEngineering microbiology · 2022Review
- Type B CTD Proteins Secreted by the Type IX Secretion System Associate with PorP-like Proteins for Cell Surface Anchorage.International journal of molecular sciences · 2022Article
- A unique bacterial secretion machinery with multiple secretion centers.Proceedings of the National Academy of Sciences of the United States of America · 2022Article
- Dynamic proton-dependent motors power type IX secretion and gliding motility in Flavobacterium.PLoS biology · 2022Article
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Authors and funding
8 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component.
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