Figure 3.

BIRD acts as an activation domain on the HIS4 promoter. (A) In vivo effect of the deletions in Bas1p on HIS4–LacZ reporter gene activation. The bas1BAS2 (Y329, yellow and red boxes) and bas1bas2 (L4233, light and dark blue boxes) cells were co-transformed with a plasmid carrying the HIS4–LacZ fusion and the different plasmids YPL-BAS1 as in Figure 2B. Transformed cells were grown in the presence (red and dark blue boxes) or absence (yellow or light blue boxes) of adenine and β-Gal assays were performed as described in Materials and Methods. (B) In vivo effects of the deletions in Bas1p on endogenous HIS genes expression. Y329 (bas1BAS2) cells were transformed with either the YPL empty control plasmid (vector) or the YPL-BAS1 plasmids and were treated as described in the legend to Figure 1B.