FIG. 5.

Transcriptional properties of the TBP mutants. (A) Artificial-recruitment assay. The indicated LexA-TBP derivatives were tested for their abilities to activate transcription from a promoter containing four LexA binding sites upstream of the GAL1 promoter and lacZ structural gene. LexA-T124N ΔG125 was not tested because the fusion protein is unstable in vivo. (B) Double-mutant analysis. Mutations that greatly diminish binding to TFIIA (N2-1), TFIIB (E186A and E188A), or TATA elements (V161A) were introduced into the context of the TBP mutants described here. Growth of 10⁴ JGY100 cells containing the resulting single and double mutants on medium lacking histidine in the presence of either 0.05 or 2% glucose is shown.