Figure 3.

Examples of three-way interactions in the two-hybrid system as scored by expression of the ADE2 gene. Each row shows a combination of two Gal4p-fusion proteins plus a third protein produced from the 2μ plasmid. The plasmids are given in Table 2. The two plates on the left indicate growth after 4 d, and the two on the right show growth after 5 d. The medium for selection of the plasmids is SD-trp,-leu,-ura. Interaction between proteins confers adenine prototrophy. The medium for selection of the plasmids and the reporter is SD-trp,-leu,-ura,-ade. The scoring designation for each combination is given in the last column.