FIG. 3.
TBP mutants specifically increase expression from enhancerless or repressed promoters. (A) Analysis of a promoter repressed by Sin3-Rpd3 histone deacetylase in which two copies of URS1 are located upstream of the CYC1 promoter and HIS3 structural gene. Strains containing the indicated TBP derivatives were examined for growth in the presence or absence of 2 mM AT. (B) Analysis of a his3 promoter derivative lacking all elements upstream of the TATA region. Strains containing the indicated TBP derivatives were examined for growth in the absence of histidine. (C) S1 protection analysis showing increased SUC2 and SUC2-HIS3 RNA levels in strains containing the indicated TBP derivatives; RNA levels were normalized to the tRNAw control. SUC2-HIS3 levels were not measured for the V71R and T124NΔG125 strains. (D) S1 analysis showing that TBP mutants do not increase transcription from moderate or strongly activated promoters. Strains containing his3 core promoters activated by Rap1 or Ace1 and the indicated TBP derivatives were assayed for transcription of HIS3 (+1, +13, and +22 transcripts are indicated), CMD1, PGK1, DED1, and tRNAw. wt, wild type.