Figure 3. Pyrophosphorolysis by WT and D₂₁₁N Ty1 RT of a blunt-ended primer terminus.

Pyrophosphorolysis reactions of WT or mutant D₂₁₁N Ty1 RT were carried out under same conditions as Fig. 2 in the presence of 10 mM Mg²⁺, using 5′ ³²P-end labeled 28-mer/14-mer substrate (RAG*928/998, Fig. 1). A, represents time course of WT reactions in seconds in the presence or absence of PPi. B, represents time course of D₂₁₁N reactions with or without PPi. Control reactions are in the absence of Mg²⁺ or enzyme.