Main steps of predicting PROTAC structures. (A) Warheads are docked to component proteins. Green and magenta arrows indicate attachment points to the E3 ligase and target warheads, respectively. (B) Half-linker conformations are generated and attached to each protein-bound warhead. The small colored spheres represent the half-linker end points. In the VHL:MZ1:BRD4BD2 (PDB ID: 5T35) complex shown, the BRD4 warhead and the end points of the attached half-linkers are depicted in cyan, and the VHL warhead and the end points of the attached half-linkers are in orange. (C) Generating favorable protein-protein poses that have half-linker ends placed sufficiently close to each other. (D) Selection of low energy poses. (E) A resulting pose with half-linker end points in close proximity before connecting the half-linkers. (F) The VHL–ElonginC–ElonginB–Cul2–Rbx1 structural assembly with the CRL2VHL complex shown in blue. The assembly includes a ubiquitin-like protein (ULP), shown in yellow, separated by a favorable distance to facilitate transfer of ubiquitin to the target. The figure also include a schematic outline of the PROTAC system.