FIG. 1.

Mutation of Pho2 and Pho4 binding sites at the PHO5 promoter. The locations of the Pho4 and Pho2 binding sites as determined by in vitro footprinting (5) are indicated by solid and open bars, respectively, the width of the bars corresponding to the relative affinities of the sites for the factor. Mutated regions within the Pho2 binding sites are in boxes (M1 to M5), and the changed nucleotides are shown above the wild-type sequence. Mutations within the Pho4 consensus sequence are shown below the wild-type sequence and are referred to as UASp1-mut, UASp2-mut, and Pho4 Site3-mut.