Yersinia pestis pH 6 antigen forms fimbriae and is induced by intracellular association with macrophages

Mol Microbiol. 1993 Apr;8(2):311-24. doi: 10.1111/j.1365-2958.1993.tb01575.x.


Ability to express pH 6 antigen (Ag) is necessary for full virulence of Yersinia pestis; however, the function of the Ag in pathogenesis remains unclear. We determined the nucleotide sequence of a 4232 bp region of Y. pestis DNA which encoded the pH 6 Ag structural gene (psaA) and accessory loci necessary for Ag synthesis. Protein sequences encoded by the Y. pestis DNA were similar to accessory proteins which function in the biosynthesis of Escherichia coli fimbriae Pap, K88, K99 and CS3 as well as the molecular chaperone for the Y. pestis capsule protein. Electron microscopy and immunogold labelling studies revealed that pH 6 Ag expressing E. coli or Yersinia produced flexible 'fibrillar' organelles composed of individual linear strands, multiple strand bundles or wiry aggregates of PsaA. Y. pestis associated with the murine macrophage-like cell line, RAW264.7, expressed pH 6 Ag in an intracellular acidification-dependent manner. Together with an earlier study showing that a Y. pestis psaA mutant was reduced in virulence, these results demonstrate that the expression of fimbriae which are induced in host macrophages is involved in plague pathogenesis.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Antigens, Bacterial*
  • Bacterial Adhesion
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Chaperonins
  • Consensus Sequence
  • DNA, Bacterial / genetics
  • Escherichia coli / metabolism
  • Fimbriae, Bacterial / metabolism*
  • Fimbriae, Bacterial / ultrastructure
  • Gene Expression Regulation, Bacterial*
  • Hydrogen-Ion Concentration
  • Macrophages / microbiology
  • Macrophages / physiology*
  • Molecular Sequence Data
  • Mutagenesis, Insertional
  • Open Reading Frames
  • Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Species Specificity
  • Yersinia pestis / genetics
  • Yersinia pestis / physiology*
  • Yersinia pestis / ultrastructure
  • Yersinia pseudotuberculosis / genetics


  • Antigens, Bacterial
  • Bacterial Proteins
  • DNA, Bacterial
  • Proteins
  • Recombinant Fusion Proteins
  • pH 6 antigen, Yersinia
  • Chaperonins

Associated data

  • GENBANK/M86713