FIG. 7.

Analysis of three downstream subregions that are important for MTE and DPE activity. (A) Diagram of the Inr and downstream core promoter subregions. The relative locations of the elements are drawn approximately to scale. (B) Systematic analysis of three downstream subregions of the wild-type Tollo core promoter. A set of promoters with all possible combinations of the m18-22, m27-29, and m30-33 mutations in the Tollo core promoter was constructed. For each promoter, the wild-type (+) and mutant (−) versions of each sequence are indicated. The numbers below each promoter construct are the mean of three or four independent experiments relative to the wild-type Tollo promoter. (C and D) Analysis of three downstream subregions in E74B- and Doc-based core promoters. The relative contributions of the 18-22, 27-29, and 30-33 subregion sequences were tested by using the hybrid E74B+MTE and Doc+MTE core promoters, which consist of the natural E74B and Doc promoters containing the Tollo MTE sequences from +18 to +27 relative to the A₊₁ in the Inr. Thus, the hybrid promoters contain Inr, MTE, and DPE motifs. Beginning with each hybrid promoter, a set of promoters that comprises all possible combinations of the m18-22, m27-29, and m30-33 mutations was constructed. For each promoter, the wild-type (+) and mutant (−) versions of each sequence are indicated. The numbers below each promoter construct indicate the mean of three or four independent experiments relative to the hybrid core promoter containing the optimal sequences in the Inr, MTE, and DPE motifs.