Fig. 4.

Structure alignment of the top 3 hits from screening of the chymotrypsin inhibitors. (A) The query structure (PDBID 1acb, chain I) and the patch (gray mesh). (B–D) The structures of the top hits aligned with the query structure [(B): PDBID 1cho, chain I; (C): PDBID 1p2n, chain B; (D): PDBID 2sec, chain I]. The hit protein structures are aligned using the best matching patches [white mesh (B–D)] with the query patch [gray mesh (A)]. Note that 2 of the hits, basic pancreatic trypsin inhibitor (C) and Turkey ovomucoid third domain (B), have a completely different fold and sequence from the query inhibitor structure. Alignment of these 2 structures is almost impossible to achieve based on sequence or fold alignment.