FIGURE 7.

The TREX1^R114H/R114H dsDNA degradation activity is more dysfunctional than the ssDNA exonuclease activity. Exonuclease time course reactions (200 μl) were prepared containing nicked dsDNA plasmid 1 (10 μg/ml = 1.6 nm nicks) and 7.6 nm TREX1^WT (A) and 260 nm TREX1^R114H/R114H (B). The samples (20 μl) were removed prior to enzyme addition (lanes 2 and 5) and after incubation for the indicated times (A, lanes 3 and 4; and B, lanes 7–12). The reaction products were subjected to electrophoresis on agarose gels. Lanes 1 and 5 (ds) contain the supercoiled dsDNA plasmid 1. The positions of migration of Form I supercoiled dsDNA (dsDNA), Form II nicked dsDNA (Nicked dsDNA), and circular ssDNA (ssDNA) are indicated.