FIG. 10.
The interaction between Cao1 and Atx1 is similar to that of Ccc2-a and Atx1 and is enhanced under low-copper conditions. (A) Schematic diagrams of the LexA DNA binding domain and fusions with Cao1 and the putative N-terminal cytosolic domain of the S. pombe Ccc2 polypeptide (Ccc2-a) are depicted at left. The VP16 and chimeric VP16-Atx1 and VP16-Atx1(R,K) molecules used as prey are shown at right. (B) Mid-logarithmic-phase cells cotransformed with the indicated plasmids were grown under basal or copper-deficient (1 mM TTM) conditions or with excess copper (100 μM CuSO4) for 5 h. Protein-protein interactions were detected by liquid β-galactosidase assays, and results are indicated in Miller units. Error bars indicate the standard deviations of samples analyzed in triplicate.