Fig. 4.

Graphical 2D and 3D representations of the binding modes of lamellarin analogues 1 (A and B) and 8 (C and D) with HIV-1 integrase STC. In the 3D representations (A and C), red ribbons depict HIV-1 integrase, grey strand is DNA, whereas green, blue and orange colours depict Asp64, Asp116 and Glu152, respectively, and round pink sphere represents Mg²⁺ metal ion cofactor. Bold red lines depict π−π stacking interactions, a guanine base in turquoise forming π−π stacking interactions with the lamellarin ligands and dotted green lines representing hydrogen bonds. The measured distances of the hydrogen bonds are shown with amino acids Cys65, Asp64, Glu92 and His67 to be 3.24, 2.60, 3.12 and 3.01 Å for analogue 1 (B), and 2.68 Å with Glu92 for analogue 8 (D). Hydrophobic interactions with residues and guanine base are depicted as red lashes in the 2D representations.