Figure 2

Structure of A_2A-StaR2-b _RIL562-ligand complexes. (A) Structure of the A_2A-StaR2-b _RIL562-Theophylline complex (PDB: 5MZJ) shown in cartoon, with helices coloured differently from blue (helix 1) to red (helix 8). Theophylline is shown as sticks within the 1.0 σ contoured 2mFo-dFc electron density maps (blue mesh) carved around the ligand. Interesting orthosteric binding site residues are shown as sticks. 1.0 σ contoured 2mFo-dFc and 3.5 σ contoured mFo-dFc ligand omit electron density maps (blue and green meshes respectively) reflecting the quality of ligand (purple sticks) fitting are shown in the top panel, whereas the lower panel provides interaction details between A_2A-StaR2-b _RIL562 binding site residues (sticks) with Tozadenant (B), LUAA47070 (C) or Vipadenant (D). In these figures, water molecules are represented as red spheres whereas hydrogen bonding is highlighted by dotted lines. An overlay of structures of ZM241385 in complex with A_2A-StaR2-b _RIL562 from either a bespoke preparation (PDB: 5UI4) (cyan) or from a soaking experiment (orange), and with A_2A b _RIL562 (PDB: 4EIY) (white) depicts the high degree of conservation in positioning of orthosteric binding site residues (E). Residues and water molecules involved in ligand binding within a 5 Å radius are represented as sticks and as spheres respectively. Hydrogen bonds are shown as dotted lines and the 1.0 σ contoured 2mFo-dFc and 3.5 σ contoured mFo-dFc ligand omit electron density maps corresponding to ZM241385 from the soaking experiment are represented as blue and green meshes respectively, carved around the ligand. Similarly electron density maps and interactions are shown for A_2A-StaR2-b _RIL562-Compound 4e generated from bespoke crystallisation (F) or from either 1 hour (G) or 24 hour (H) soaks of A_2A-StaR2-b _RIL562-Theophylline crystals with Compound 4e.