Figure 6.
Promoter melting in cells containing various TFIIB mutants. (A) Shown are β-galactosidase activity assay results of the ADH1–lacZ reporter gene in yeast cells (grown at 30°C) containing the indicated TFIIB proteins. The reporter was under the control of either LexA alone or LexA–VP16. (B) Shown are in vivo permanganate footprint results to detect transcription-induced DNA strand separation in the promoter region of the ADH1–lacZ reporter gene. The TATA box and the two major start sites are marked. Yeast cells (grown at 30°C) either contained wild-type TFIIB (WT) or the indicated TFIIB mutants (70A5 and 79A5), with the reporter gene activated by either LexA alone or LexA–VP16. Lane 1 is a DNA sequencing C ladder. Lane 2 shows the results for yeast DNA that was treated with KMnO4 in vitro.