Functional analysis of the CepR binding site. A. Site directed mutagenesis was used to determine the effects of mutations on the luminescence activity of a cepI::luxCDABE fusion. The sequence upstream of the CepI ORF is shown. The ATG start codon is indicated by bold lettering and the predicted -10 hexamer is underlined. A series of 4 bp substitutions used to mutate the promoter region are indicated as bx303-313 and the cep box consensus sequence is enclosed in the rectangle. B. Expression of the cepI::luxCDABE fusions in B. cenocepacia K56-2. Luminescence (CPM) was measured at 22 hours and is represented as CPM/O.D. The numbers on the x axis indicate K56-2 (pCPI303-313) respectively. WT is K56-2 (pCPI301) and the vector control is K56-2 (pMS402).