Phenotypic features of the E244G and Q951G mutations. A, an immunoblot of purified plasma membrane (PM) vesicles prepared from various strains of yeast. N242K was previously shown to have WT levels of Pdr5 in the plasma membrane (6). Samples containing 20 μg PM vesicle protein were solubilized in SDS-PAGE for 30 min at 37 °. Conditions for gel electrophoresis and Immunoblotting were previously described (6). The blots were simultaneously treated with a 1:1000 dilution of antiPdr5 and anti Pma1 antibodies. The latter serves as a loading control. Pertinent molecular weights are given in kDa. Pdr5 is 160 kDa and Pma1 is 99.6 kDa. The lanes are as follows: lane 1, WT; lane 2, Δpdr5; lane 3, E244G; lane 4, Q951G; lane 5, E244G, Q951G; Quantitative analysis of B, cyh and C, clo resistance. Cultures containing drug were set up and grown as described (6). The plots and statistical analysis were carried out using GraphPad Prism software. The figures show the mean values of three independent experiments and the error bars represent the S.D. In these panels the strains are designated as follows: ▲ is WT, ■ is S558Y, ▼ is E244G, ◆ is Q951G, ● (---) is E244G, Q951G.