Fig. 1.

Primer extension assays of norV, fes, ydiE, grxA, ahpC, katG, sodA, uspA, hmpA, and ygbA expression in wild-type and isogenic regulatory mutants. The parent MG1655 and Δfur, ΔnorR, ΔoxyR, ΔsoxRS, and ΔmetR mutant strains were grown to OD₆₀₀ = 0.4–0.6 in LB medium, pH 6. Cultures were split, and aliquots were left untreated or treated with 1 mM H_2O2, NaNO₂, or GSNO. After 5 min, total RNA was isolated from each untreated and treated culture. All assays were carried out by using 5 μg of the same RNA preparation.