Figure 4. Tryptophan biosynthesis rescues cells from ROS.

A) A schematic of the tryptophan biosynthesis pathway [29]. PRA: N-(5′-phospohribosyl)-anthsranilate, CDRP: 1-(o-carboxyphenylamino)-1-desoxyribuose-5-phosphate. B) Compound sensitivity of selected mutant strains were analyzed by spot assay. Strains were grown in liquid YPD+G418 overnight at 30°C and then diluted in YPD. Ten-fold serial dilutions of each yeast culture was spotted onto YPD plates in the absence (control) and presence of the different compounds: MMS (0.006%), MEN (40 µM), HYQ (3 mg ml⁻¹), and tBuOOH (0.75 mM). Plates were incubated at 30°C and growth was recorded after 48 h exposure.