FIG. 3.

Determination of the core responsive segments in RE I-2 and RE II. (A) Responsiveness of REs I-2A, I-2B, and I-C of the RE I-2 region. (B) Responsiveness of RE IIA, RE IIB, and RE IIC of the RE II region. (C) Responsiveness of REs IIC-1 and II-C2 of the RE II-C region. The smaller segments of RE I-2, RE II, and the further RE IIC region (see Fig. 1A) were arranged as three to five tandem repeats upstream of the E1B minimal TATA box, which was followed by a firefly luciferase gene. The assay was performed as described in Materials and Methods. The value of perpendicular axis denotes the fold activity calculated as the normalized activity obtained with RTA divided by that obtained without RTA as in Fig. 2.