FIG. 1.

Identification of the parRS operon. (A) Fold induction of pPA3552::lux fusion in BM2-glucose minimal medium supplemented with 2 mM Mg²⁺ in the presence of 4 μg/ml indolicidin compared to induction in the absence of indolicidin in the WT (H103) and mutant strains UW-PA1798 (UW-1798) and UW-PA1799 (UW-1799). The pPA3552::lux fusion contained a promoterless lux cassette fused to the promoter of the arnB gene and reported on the transcription of the eight-gene operon encoding the arn LPS modification operon. The results provided correspond to one representative experiment of at least three independent assays which displayed the same trends. (B) Schematic representation showing the genomic context of the parRS operon. The black arrows represent ORFs.