Autoregulation of the Pseudomonas aeruginosa protein PtxS occurs through a specific operator site within the ptxS upstream region.

ABSTRACT: We have previously shown that the Pseudomonas aeruginosa toxA regulatory protein PtxS autoregulates its own synthesis by binding to a 52-bp fragment. The 3' end of the 52-bp fragment is located 58 bp 5' of the ptxS translation start site. We have identified a 14-bp palindromic sequence (TGAAACCGGTTTCA) within the 52-bp fragment. In this study, we used site-directed mutagenesis and promoter fusion experiments to determine if PtxS binds specifically to this palindromic sequence and regulates ptxS expression. We have also tried to determine the roles of specific nucleotides within the palindromic sequence in PtxS binding and ptxS expression. Initial promoter fusion experiments confirmed that the 52-bp fragment does not overlap with the region that carries the ptxS promoter activity. PtxS bind

SUBMITTER: Swanson BL 

PROVIDER: S-EPMC101966 | biostudies-literature | 2000 Aug

REPOSITORIES: biostudies-literature