Figure 6.

Overexpression of non-DNA-tethered activating regions does not enhance transcriptional activation elicited by nonclassical activators. The Gal4 constructs were expressed from the ADH1 promoter on a high-copy (2 μ) vector; Gal4 + Gal80 was carried on an ARS-CEN vector. RII + RII is comprised of two tandemly fused copies of the Gal4-activating region and RII + Gcn4 comprises the same RII moiety fused to Gcn4 lacking its DNA-binding domain. Both of these activating regions were expressed from the β-actin promoter and carried on a 2 μ plasmid. Transcriptional activity was measured as β-galactosidase units in yeast strain ZZY41.