Fig. 5

The H-bond network along the IL-1α/SL1067 binding interface is mediated by a Na⁺ ion and three water molecules. a W1, W2, W3, OD1(Asp64), O(Asp65), and O21(2Nap-dU7) are coordinated by a sodium ion. Additional H-bonds are formed with the surrounding residues from either IL-1α or SL1067: W1-O (Asp64), W2-O2 (2Nap-dU10), O(Ala66)-W3-O2(dU10). The lengths of these H-bonds are listed in Supplementary Tables 4 and 5. b The same view of the H-bond network as shown in a. 2Fo–Fc electron density for the Na⁺ ion and surrounding water molecules is shown in gray mesh and contoured at 1σ. c Wall-eyed stereo image of the IL-1α/SL1067 crystal structure. Electron density from the final 2Fo–Fc map contoured at 1.0σ. SL1067 is colored orange and the protein is colored in green. Red spheres depict associated water molecules