Characterization of the Porphyromonas gingivalis Type IX Secretion Trans-envelope PorKLMNP Core Complex

J Biol Chem. 2017 Feb 24;292(8):3252-3261. doi: 10.1074/jbc.M116.765081. Epub 2017 Jan 5.


The transport of proteins at the cell surface of Bacteroidetes depends on a secretory apparatus known as type IX secretion system (T9SS). This machine is responsible for the cell surface exposition of various proteins, such as adhesins, required for gliding motility in Flavobacterium, S-layer components in Tannerella forsythia, and tooth tissue-degrading enzymes in the oral pathogen Porphyromonas gingivalis Although a number of subunits of the T9SS have been identified, we lack details on the architecture of this secretion apparatus. Here we provide evidence that five of the genes encoding the core complex of the T9SS are co-transcribed and that the gene products are distributed in the cell envelope. Protein-protein interaction studies then revealed that these proteins oligomerize and interact through a dense network of contacts.

Keywords: bacterial pathogenesis; membrane protein; microbiology; protein assembly; protein complex; protein purification; protein secretion; secretion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / analysis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Bacterial Secretion Systems / analysis
  • Bacterial Secretion Systems / genetics
  • Bacterial Secretion Systems / metabolism*
  • Bacteroidaceae Infections / microbiology
  • Crystallography, X-Ray
  • Genes, Bacterial
  • Humans
  • Porphyromonas gingivalis / chemistry
  • Porphyromonas gingivalis / genetics
  • Porphyromonas gingivalis / metabolism*
  • Protein Interaction Maps
  • Protein Subunits / analysis
  • Protein Subunits / genetics
  • Protein Subunits / metabolism


  • Bacterial Proteins
  • Bacterial Secretion Systems
  • Protein Subunits

Associated data

  • PDB/3BRY