title: Regulation of exoprotein gene expression in Staphylococcus aureus by agar.
abstract: 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: D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification; D004251:DNA Transposable Elements; D004591:Electrophoresis, Polyacrylamide Gel; D005798:Genes, Bacterial; D005809:Genes, Regulator; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics; D013211:Staphylococcus aureus / Q000235:genetics* / Q000472:pathogenicity; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D012333:RNA, Messenger