Fig. 6.

DNase I protection analysis of various quorum-controlled promoters. (A) End-labeled fragments ≈280 bp in length were incubated without LasR (lane 2) or with LasR (lane 3) in the presence of 5 μM 3OC12-HSL. Lane 1 shows a Maxam–Gilbert A+G sequencing ladder of the respective probe. The hcnA and PA3904 fragments were end-labeled on the coding strand, and the lasB, PA0572, and PA4677 fragments were end-labeled on the noncoding strand. The black boxes indicate the regions protected by LasR, and the open box shows the position of the predicted OP1 sequence. The shaded areas within the protected sequences indicate predicted 20-bp las–rhl boxes. (B) Promoter region of the lasB gene showing the relative locations of OP1 and OP2.