FIG. 1.

Effects of single-base-substitution lux box mutations on promoter activity. Every nucleotide in the lux box was replaced with the three other ones. The sequence of a wild-type lux box and the nucleotide numbering system used are shown on the bottom, and activity is expressed as percent of wild-type activity. Experiments were performed with recombinant E. coli cells containing the LuxR expression vector pHV402 and a plasmid containing a lux promoter-gfp transcriptional fusion with a lux box nucleotide substitution as indicated. Cultures were grown with 3OC6-HSL. The results represent the means of the results of three independent experiments, and the error bars represent standard deviations from the means.