FIGURE 3.

A, functional complementation of ΔARG4 yeast strain transformed with the high copy pYES2.1-V5-His-TOPO vector expressing the different mutated ASL alleles. The cells were grown in plates with synthetic minimal medium lacking uracil and arginine, and expression was induced with 2% galactose (GAL). B, strains displaying residual growth in the above conditions were grown in 2% raffinose with 0.01% galactose to induce lower ASL expression. C, mutants allowing residual growth when expressed form the low copy pFL38 plasmid with 2% galactose were grown in 2% raffinose with 0.01% galactose to induce minimal ASL expression. Letter codes are as in Fig. 2.