CQ possibly affects multiple biological functions.

<p>A. Representative yeast haploid deletion mutants exhibiting the highest levels of sensitivity to CQ. B. Suppression of CQ-hypersensitivity of the <i>fet3Δ</i> and <i>thi3Δ</i> mutants by exogenously supplied iron [Fe(III)] and thiamine (Thi), respectively. C. Yeast tetrad analysis of the synthetically sick interaction between <i>thi3Δ</i> and <i>thi7Δ</i>. Colonies of the <i>thi3Δ thi7Δ</i> double mutant were all circled. D. Increased CQ-sensitivity of a <i>thi3Δ thi7Δ</i> double mutant as compared to either single mutant. E. Dosage-dependent suppression of CQ-hypersensitivity of the <i>thi3Δ thi7Δ</i> double mutant by exogenously supplied thiamine. F. Suppression of CQ-hypersensitivity of the <i>thi3Δ thi7Δ</i> double mutant by overexpressing <i>THI3</i>, <i>THI7</i>, and <i>PDC2</i>. G. Suppression of CQ-hypersensitivity of the <i>thi3Δ</i> single mutant by overexpressing <i>THI7</i> and <i>PDC2</i>.