FIGURE 5.

5′-Adenylation is successful for any 5′-terminal RNA nucleotide. RNA substrates S1–S4 (which differ only in their 5′-terminal nucleotide X) were annealed with the +3/0 blocking oligo and assayed for 5′-adenylation as in Figure 3 ▶. std, RNA substrate incubated without T4 RNA ligase for 6 h. For all sets of lanes, the four time points are at 0.5 min, 10 min, 1 h, and 6 h (20% PAGE).