FIGURE 7.

Dependence of 2′-PO₄ removal on ChaetTpt1 concentration. Reaction mixtures (10 µL) containing 100 mM Tris-HCl (pH 7.5), 1 mM NAD⁺, 0.2 µM (2 pmol) 5′ ³²P-labeled 10-mer pRNA^2′p, or pRNA_3′p substrates (shown at top), and ChaetTpt1 as specified were incubated at 37°C for 30 min. The reaction mixtures were analyzed by urea-PAGE. The extents of product formation are plotted as a function of input enzyme. Each datum is the average of three independent titration experiments ±SEM.