Figure 8.

Proposed model of preferential degradation of unprocessed DNA and resistance of 3’-processed DNA to TREX1. (A) The panel represents TREX1 activity (generic shape shown in brown) with unprocessed HIV-1 DNA substrate shown in blue-red blunt ended dsDNA. (B) Degradation of 3’-processed HIV-1 DNA substrate by TREX1 shown in blue-red sticky ended double strands. A schematic representation showing that TREX1 degrades the unprocessed HIV-1 DNA which is blunt-ended and integration-incompetent at a faster rate, whereas the integration-competent 3’-processed HIV-1 DNA is turned over at a relatively slower rate. This kinetic mechanism allows the 3’-processed HIV-1 DNA to undergo integration into the human genome.