Cloning, Sequencing and Structural Manipulation of the Enterotoxin D and E genesfrom Staphylococcus aureus. (Annual Summary Report for November 1, 1987-June 30, 1989)

摘要

The regulation of the enterotoxin D (sed) has been investigated. Transcription inS. aureus initiates from a single promoter, but in E. coli 3 promoter sites were mapped. Activation of the staphylococcal promoter is dependent upon the product of the agr locus. In addition, another regulatory locus is operational and appears to be dependent on spacing of the end of the mRNA from the translational start codon. Deletion analysis of the exfoliative toxin A gene has been initiated. A 72 amino acid C-terminal peptide was found to have exfoliative activity. However in vitro deletions of the gene to produce truncated toxin molecules missing portions of the C-terminus were transcriptionally inactive. Present evidence suggests that the 3' end of the Eta mRNA is important for message stability. A new regulatory locus that affects lipase production has been identified. Mutations in this region of the genome reduce lipase expression more than 90%. The locus has been cloned and efforts to identify regulatory gene products are underway. Keywords: Biotechnology, Cloning, Enterotoxins, Sequencing, Staphylococcus aureus, Toxins. (jes)