The plasmid-encoded Yop2b protein of Yersinia pseudotuberculosis is a virulence determinant regulated by calcium and temperature at the level of transcription

Mol Microbiol. 1988 Mar;2(2):237-45. doi: 10.1111/j.1365-2958.1988.tb00025.x.


The basic Yop2b protein, encoded by the virulence plasmid pIBI of Yersinia pseudotuberculosis, is produced under Ca2+-deficient conditions. A mutant deleted for the entire yopH gene, which encodes the Yop2b protein, was found to be avirulent. Virulence could be restored by trans-complementation. The DNA-sequence of yopH predicted a 50 737 D polypeptide lacking a typical signal peptide. Transcription of yopH is regulated by both temperature and Ca2+-concentration. Mutations within the region of the virulence plasmid known to be involved in regulating gene expression in response to Ca2+ abolished transcription of yopH. Other temperature-sensitive mutations in the Ca2+-regulatory locus showed a high level of transcription regardless of Ca2+-concentration. These responses were similar to those of the yopE gene. The promoter region of the yopE and yopH genes were compared and four conserved motifs identified.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Outer Membrane Proteins*
  • Bacterial Proteins / genetics*
  • Base Sequence
  • Calcium / pharmacology*
  • DNA Restriction Enzymes
  • Genes* / drug effects
  • Genes, Bacterial* / drug effects
  • Molecular Sequence Data
  • Mutation
  • Nucleotide Mapping
  • Plasmids* / drug effects
  • Temperature
  • Transcription, Genetic* / drug effects
  • Virulence
  • Yersinia pseudotuberculosis / genetics*
  • Yersinia pseudotuberculosis / pathogenicity


  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Yop2b (Yersinia)
  • DNA Restriction Enzymes
  • Calcium

Associated data

  • GENBANK/Y00551