FIG. 4.

Nucleotide incorporation into the 3′ end of a synthetic RNA by Trf4. Trf4 (10 nM) was incubated with a synthetic 40-mer RNA substrate (20 nM) and increasing concentration of a single nucleotide for 5 min at 30°C. Reaction products were resolved on a 15% polyacrylamide gel containing 8 M urea followed by PhosphorImager analysis.