Figure 6. Effect of disulfide stress on RNA capping and degradation in E. coli.

(A) Presence of capped yeiP mRNA in diamide-treated cells. Total RNA from E. coli cells that had or had not been treated with diamide was analyzed by boronate gel electrophoresis and Northern blotting, with or without prior decapping with RppH (PPase). See also Fig. S2E.

(B) Inactivation of ApaH by cadmium and diamide. Purified ApaH was treated with cadmium chloride or diamide, and the decapping activity that remained was analyzed by boronate gel electrophoresis and blotting, using yeiP mRNA from a ΔapaH strain of E. coli as a substrate.

(C) Slow decapping of yeiP mRNA in cells experiencing disulfide stress. The indicated strains of E. coli growing in MOPS-glucose were treated first with cadmium chloride and then with rifampicin, and equal amounts of total RNA extracted at time intervals thereafter were analyzed by boronate gel electrophoresis and blotting. Data from representative experiments are shown. See also Fig. S2F.