Fig. 3.

ppGpp synthesis is reduced in the absence of quality control by PheRS editing. ppGpp levels were normalized to OD₆₀₀ in pheA auxotrophic strains with either wild-type PheT (solid bars) or editing-deficient PheT(G318W) (checkered bars) strains grown to early log phase in dropout medium containing high Phe (0.5 mM), low Phe (10 µM), or low Phe and m-Tyr (0.2 or 0.4 mM). Error bars represent the SD from three independent experiments.