FIGURE 3.

Chromatin remodeling of the induced CHA1 promoter occurs normally in yeast harboring Mediator tail mutants that are defective for CHA1 transcriptional activation. MNase cleavage sites were mapped relative to the BamHI site at +602 in the CHA1 ORF in chromatin prepared from yeast grown in CSM without or with 1 mg/ml of serine (30 min induction). Increasing amounts of MNase were used for each sample as indicated by the triangles at the bottom; the lowest level in each group corresponds to no MNase addition, and the highest to 50 units/ml. Marker lanes (M) contain 100-bp DNA ladders. The small arrow in each panel indicates the strong cleavage induced by serine addition in the vicinity of the CHA1 TATA element.