Regulation of exoprotein gene expression in Staphylococcus aureus by agar

Mol Gen Genet. 1986 Jan;202(1):58-61. doi: 10.1007/BF00330517.


Insertion of the erythromycin-resistance transposon Tn551 into the Staphylococcus aureus chromosome at a site which maps between the purB and ilv loci has a pleiotrophic effect on the production of a number of extracellular proteins. Production of alpha, beta and delta hemolysin, toxic shock syndrome toxin (TSST-1) and staphylokinase was depressed about fifty-fold while protein A production was elevated twenty-fold. Hybridization analysis showed that the defect in expression of TSST-1 and alpha hemolysin was at the transcriptional level. Inability of the mutant strain to express either a cloned TSST-1 gene or the chromosomal gene indicates that the transposon has inactivated a trans-active positive control element. This element has been designated agr for accessory gene regulator.

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / isolation & purification
  • DNA Transposable Elements
  • Electrophoresis, Polyacrylamide Gel
  • Genes, Bacterial*
  • Genes, Regulator*
  • Nucleic Acid Hybridization
  • RNA, Messenger / genetics
  • Staphylococcus aureus / genetics*
  • Staphylococcus aureus / pathogenicity
  • Transcription, Genetic


  • Bacterial Proteins
  • DNA Transposable Elements
  • RNA, Messenger