The predicted interactions of rucaparib (upper-left panel) and M324 (upper-right panel) on PLK2 kinase (PDB:4I5M) using the molecular docking environment (MOE) software are shown in the upper panel. Dashed green and magenta lines indicate hydrogen bonds and hydrogen-pi interactions, respectively. The superposed predicted binding conformations of M324 and rucaparib are displayed on the bottom left panel. As it can be observed, they adopt distinct conformations, with the amine of rucaparib moving away from the positively charged residues Lys57 and Arg136. The bottom right panel shows the electrostatic surface map around the binding pocket of PLK2 kinase with the binding pose of M324. The surface is colored by electrostatic potential using a continuous spectrum from blue (most positive), through white (neutral) to red (most negative). Two positively charged residues (Lys57 and Arg136) indicate the favorable electrostatic interaction with the negatively charged carboxylic acid moiety of M324.
