Different sequences between Cbf1 and Met31/32 binding sites show a range of reporter gene activation. (A) Serial dilutions of yeast containing reporter plasmids with the same distance (20 bp) between binding sites, but different spacer sequences. Yeast strains were grown on the indicated media for 5 days at 30°C. (B) Proportions of transformants that displayed moderate to high levels of growth on solid media with 10 mM or 25 mM 3-AT. For each distance between binding sites, growth rates of 72 transformants with different spacer sequences were assayed with serial dilutions. Average growth rates in liquid media with 1 mM 3-AT, as in Figure 4, is also shown for comparison purposes.