3. The catalytic domain has an RNaseH-type fold and belongs to the superfamily of polynucleotidyl transferases. The active site is comprised of two Asp residues and one Glu, in the typical DDE motif, each of which is required for catalysis.

4. four criteria to conclude that integrase is theinhibitor target: 1. found to be active against recombinant integrase. 2. infected cells treated with the drug must show an accumulation of 2-LTR circles, resulting from the accumulation of viral cDNA and decreased HIV integration into host 3. integrase mutations must be found in drug-resistant viruses 4, the drug should be inactive in biochemical assays against recombinantintegrases bearing the mutations identified in the drug-resistant viruses DKAs DCQ acids; DCT acids PDP SQL Quinolone derived