Figure 7.

Thermostability of ApPolη. (a) Aliquots of ApPolη (closed circles) and HsPolη (open circles) were heated to the indicated temperature for 5 minutes. The effect of this treatment on the polymerase activity was subsequently determined by analyzing the respective enzyme's ability to extend a radiolabeled primer by incorporating dCMP opposite the template G. Replication assays were performed at 37°C for 20 minutes. (b) The ability of each enzyme to extend the primer was quantified, and the specific activity compared to that of each enzyme heated at 37°C was calculated and subsequently plotted as a function of the temperature to which the enzyme was initially exposed.