FIGURE 3.

Structural analysis of the inhibitor-CCD complexes. A, the crystal structure of BI-1001 bound to the integrase CCD dimer. Surface views of individual integrase subunits are depicted in magenta and cyan. B, overlay of CCD-LEDGIN-6 (Protein Data Bank code 3LPU) and CCD-BI-1001 co-crystal structures. Schematic views of integrase subunits are colored as described in A; LEDGIN-6 and BI-1001 backbones are green and yellow, respectively. Compound oxygen and nitrogen atoms, as well as those of integrase residues Thr-174, Glu-170, and His-171, are colored red and blue, respectively (for simplicity, only main chain Glu-170 and His-171 atoms are shown). The inhibitor carboxyl groups H-bond (green and orange dashed lines for LEDGIN-6 and BI-1001, respectively) with the main chain nitrogens of Glu-170 and His-171, and to the Thr-174 side chain. The BI-1001 methoxy group forms an additional H-bond (black dashed line) with Thr-174.