2. Results We used the three-dimensional crystal structures of receptors to identify amino acids located in the active site for docking purposes. From the Protein Data Bank (PDB_ID) database, we obtained 35 three-dimensional crystal structures of proteins among the 24 receptors, which served as the active sites (pockets) for docking. Detailed information for each PDB_ID is presented in Table S3 of the Supplemental Data.