FIG. 4.

Responsiveness to RTA of the mutants of RE I-2B and RE IIC-2. Results for a mutant series of RE I-2B (A) and RE IIC-2 (B) are shown. Three to five tandem copies of each mutated fragment of RE I-2B and RE IIC-2 were placed upstream of the E1B minimal TATA box, which was followed by a firefly luciferase gene. The assay was done as described above. The value of perpendicular axis denotes the fold activity, calculated as the normalized activity obtained with RTA divided by that obtained without RTA. Mutated nucleotides of each RE are shown under the panel.