FIG. 3.

The C-terminal region of ABF1 is sufficient for activation of ARS function when fused to the GAL4 DBD. (A) Schematic diagram showing the important features of the ABF1 protein. Also indicated are the homologous regions among ABF1, RAP1, and SAN1 and those among the ABF1 proteins from S. cerevisiae (Sc), Kluyveromyces lactis (Kl), and Kluyveromyces marxianus (Km). (B) Expression of various GAL4-ABF1 fusion proteins in yeast. A final concentration of 50 μM copper sulfate was used. The proteins were detected by immunoblotting using the HA antibody. (C) Abilities of various GAL4 fusion proteins to activate the stability of the GAL4-responsive ARS1 plasmid (pARS1/-B23/G24). Cells were grown in nonselective medium at 30°C for 30 h before plating on nonselective and selective plates.