Figure 4

Enzyme activities of wt-saPolX, mutant H435A and double mutant H435A + D193A. Primer extension assays were performed on a gapped DNA substrate to check the polymerase and exonuclease activities present in wt-saPolX and exonuclease mutant H435A. The results show that wt-saPolX possesses both polymerase and exonuclease activities. The mutation H435A abolished the exonuclease activity of saPolX and the mutation D193A removed the polymerase activity.