Figure 2. Pyrophosphorolysis by WT and D₂₁₁N Ty1 RT of a recessed primer terminus.

Pyrophosphorolysis reactions by WT or mutant D₂₁₁N Ty1 RT in the presence of 10 mM Mg²⁺ and 1 mM sodium pyrophosphate were analyzed by in vitro assay as described under materials and methods using 5′ ³²P-end labeled 14-mer/28-mer substrate (RAG*998/RAG 928, Fig. 1. Labeled end is depicted by *). A, represents time course of WT reactions in seconds with or without PPi. B represents time course of D₂₁₁N reactions in seconds with or without PPi. Control reactions in both panels are in the absence of Mg²⁺ or enzyme.