FIGURE 5.

Growth of various mutant strains expressing VCX1 and VCX1-H303A in the presence of toxic concentrations of cations. Both VCX1 and VCX1-H303A were introduced into the yeast shuttle vector pYES-DEST52 using Gateway recombination as described under “Experimental Procedures.” Each construct was introduced into K667 (cnb1Δ pmc1Δ vcx1Δ) and AXT3 (ena1-2Δ nha1Δ nhx1Δ) mutant strains. Each strain was grown, and serial dilutions were made as described under “Experimental Procedures.” Five microliters of each dilution were spotted onto YPG medium with addition of a high concentration of CaCl₂ (A) or KCl (B) as indicated. Plates were incubated at 30 °C for 2–5 days.