FIG. 5.

Comparison of ABF1 and RAP1 in facilitating transcriptional activation from the HIS7 and ADE5,7 promoters. (A) The MEL1 reporter gene fused to a modified HIS7 promoter having an ABF1 binding site or RAP1 binding site or mutant ABF1 or RAP1 site adjacent to the GCN4 binding site, schematized at the top. MEL1 activity was monitored and compared in GCN4⁺ wild-type cells and in gcn4Δ cells. Standard deviations are shown. (B) The MEL1 reporter gene fused to a modified ADE5,7 promoter having an ABF1 binding site or RAP1 binding site or mutant ABF1 or RAP1 binding site adjacent to the BAS1 binding site, schematized at the top. MEL1activity was monitored and compared in BAS1 and BAS2⁺ wild-type cells and in bas2Δ cells (note different scales) in the presence and absence of adenine. Standard deviations are shown. WT, wild type.