Figure 2. Transcriptional Activity of the URE3 Motif as Assessed by URE3-driven Repression of a Reporter Gene.

The hgl5 promoter (wild type and containing the T₄A, T₄C, T₄G and C₅A mutations) was placed upstream of the luciferase reporter gene. These constructs were transfected into cultured E. histolytica trophozoites. Mutations (T₄A and C₅A) identical to those within the competing oligonucleotides were made within the hgl5 promoter URE3 motif. Luciferase values from at least three independent experiments with two different DNA preparations were performed. Luciferase values standardized to wt (100%) are shown as means with standard error. Promoter activity as a % of wild type is shown on the y axis and position and base mutated in the promoter on the x axis. All mutants were statistically different from the wild type promoter (p<0.0001 using the non-parametric Kruskal-Wallis Test).