Fig. 3.

Effect of nucleotide identity on decapping by RppH in vitro. (A) Reactivity of substrates differing in the first transcribed nucleotide. The decapping of Ap₄A4, Ap₄G4, Ap₄C4, and Ap₄U4 by RppH was monitored as in Fig. 2. (B) Reactivity of substrates differing in the cap nucleotide. (Top) 5′-terminal sequence and expected secondary structure of Ap₄A8. (Bottom) Decapping of Ap₄A8, Gp₄A8, Cp₄A8, and Up₄A8 by RppH. The 5′-terminal sequences of these substrates are shown in SI Appendix, Fig. S1. Corresponding time courses for decapping of the internal standard Ap₄A8XL by RppH are graphed in SI Appendix, Fig. S2 B and C. Each time point is the average of three or more independent measurements. Error bars correspond to SDs.