FIGURE 1.

G737V and P473L mutations of yeast TOP2 confer hypersensitivity to mAMSA. JN394t2-4 yeast cells carrying either pDED1TOP2 (G737V), pDED1TOP2 (P473L), pDED1TOP2 (T744P), or pDED1TOP2⁺ (WT) plasmid were exposed to mAMSA at 34 °C for the 24 h. Aliquots were removed, diluted, and plated to complete synthetic medium plates lacking uracil. Cell survival is expressed as the percentage of surviving cells at the time 24 h relative to the viable titer at the time drug was added (t = 0). Therefore, at the start of the experiment, the survival will be 100%, and in untreated cells the survival will be greater than 100%, reflecting cell growth over the 24-h incubation period. Error bars represent the standard deviation of three independent experiments, and in several cases, the error bars are smaller than the symbols denoting survival. The plasmid pDED1TOP2 (T744P) carries a previously described mutation that confers hypersensitivity to mAMSA (22).