The Porphyromonas gingivalis type IX secretion system (T9SS) promotes periodontal disease by secreting gingipains and other virulence factors. By in situ cryoelectron tomography, we report that the P. gingivalis T9SS consists of 18 PorM dimers arranged as a large, caged ring in the periplasm. Near the outer membrane, PorM dimers interact with a PorKN ring complex of ∼52 nm in diameter. PorMKN translocation complexes of a given T9SS adopt distinct conformations energized by the proton motive force, suggestive of different activation states. At the inner membrane, PorM associates with a cytoplasmic complex that exhibits 12-fold symmetry and requires both PorM and PorL for assembly. Activated motors deliver substrates across the outer membrane via one of eight Sov translocons arranged in a ring. The T9SSs are unique among known secretion systems in bacteria and eukaryotes in their assembly as supramolecular machines composed of apparently independently functioning translocation motors and export pores.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9170169 | PMC |
| http://dx.doi.org/10.1073/pnas.2119907119 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A unique bacterial secretion machinery with multiple secretion centers.
Proc Natl Acad Sci U S A
May 2022
Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, TX 77030.
The Porphyromonas gingivalis type IX secretion system (T9SS) promotes periodontal disease by secreting gingipains and other virulence factors. By in situ cryoelectron tomography, we report that the P. gingivalis T9SS consists of 18 PorM dimers arranged as a large, caged ring in the periplasm.
View Article and Find Full Text PDFStructural and functional analyses of the Porphyromonas gingivalis type IX secretion system PorN protein.
J Biol Chem
March 2022
Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, UMR 7257, Marseille, France; Architecture et Fonction des Macromolécules Biologiques, Centre National de la Recherche Scientifique, UMR 7257, Marseille, France. Electronic address:
Porphyromonas gingivalis, the major human pathogen bacterium associated with periodontal diseases, secretes virulence factors through the Bacteroidetes-specific type IX secretion system (T9SS). Effector proteins of the T9SS are recognized by the complex via their conserved C-terminal domains (CTDs). Among the 18 proteins essential for T9SS function in P.
View Article and Find Full Text PDFStructure and mechanism of the proton-driven motor that powers type 9 secretion and gliding motility.
Nat Microbiol
February 2021
Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
Three classes of ion-driven protein motors have been identified to date: ATP synthase, the bacterial flagellar motor and a proton-driven motor that powers gliding motility and the type 9 protein secretion system in Bacteroidetes bacteria. Here, we present cryo-electron microscopy structures of the gliding motility/type 9 protein secretion system motors GldLM from Flavobacterium johnsoniae and PorLM from Porphyromonas gingivalis. The motor is an asymmetric inner membrane protein complex in which the single transmembrane helices of two periplasm-spanning GldM/PorM proteins are positioned inside a ring of five GldL/PorL proteins.
View Article and Find Full Text PDFPorM, a core component of bacterial type IX secretion system, forms a dimer with a unique kinked-rod shape.
Biochem Biophys Res Commun
October 2020
Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, Japan. Electronic address:
Porphyromonas gingivalis, which is a major pathogen of the periodontal disease, secrets virulence factors such as gingipain proteases via the type IX secretion system (T9SS). T9SS consists of a trans-periplasmic core complex, the outer membrane translocon complex and the cell-surface complex attached on the outer membrane. PorM is a major component of the trans-periplasmic core complex and is believed to connect the outer membrane component with the inner membrane component.
View Article and Find Full Text PDFType IX secretion system PorM and gliding machinery GldM form arches spanning the periplasmic space.
Nat Commun
January 2018
Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, UMR 7257, 163 Avenue de Luminy, Case 932, 13009, Marseille, France.
Type IX secretion system (T9SS), exclusively present in the Bacteroidetes phylum, has been studied mainly in Flavobacterium johnsoniae and Porphyromonas gingivalis. Among the 18 genes, essential for T9SS function, a group of four, porK-N (P. gingivalis) or gldK-N (F.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!