FIG. 6.
A. Identification of a PIS1 promoter element required for glycerol-mediated repression. BRS1001 (wild-type) transformants containing various promoter deletions were grown in synthetic medium lacking uracil and containing either 2% glucose or 3% glycerol. Yeast extracts from the transformants were prepared and assayed for CAT activity. MRD1 is a divergent ORF. The locations of two MCEs (Mcm1p binding sites) (black box), a Rox1p binding site (gray box), potential TATA boxes (bars), three UAS elements, and a URS element are shown. B.D., below detection. B. PIS1 URSGLY element functions as a URS element. Plasmid pLGΔ312 + URSGLY, containing 25 bp of PIS1 gene promoter (−76 to −51), was transformed into a wild-type strain (BRS1001), and β-galactosidase activity was measured. Cultures were grown in Ura− 2% glucose medium.