Interaction between LEDGF/p75 and HIV Pol. Direct interaction of LEDGF/p75 with HIV-1 Pol polyprotein as determined by an AlphaScreen PPI assay. (A) Titration of Flag-LEDGF/p75WT or Flag-LEDGF/p75D366N against 20 nM GST-sPol_PRD25N. LEDGF/p75WT binds Pol with an apparent KD of 3.1 ± 1.1 nM, whereas the D366N point-mutation abolishes interaction. (B) Titration of CX05045, raltegravir (RAL) and DMSO against a constant background of 5 nM Flag-LEDGF/p75WT and 20 nM GST-Pol_PRD25N. CX05045 inhibit the interaction with an IC50 of 10.7 μM (95% CI 9.5-12.0). Data represent mean values ± standard deviations of duplicate measurements in a representative experiment. (C) Pull-down of His-MBP-sPol_PRD25N using recombinant Flag-LEDGF/p75WT or Flag-LEDGF/p75D366N.