3CQL:
reference: X-ray Structure of Papaya Chitinase Reveals the Substrate Binding Mode of Glycosyl Hydrolase Family 19 Chitinases., Huet J, Rucktooa P, Clantin B, Azarkan M, Looze Y, Villeret V, Wintjens R, Biochemistry. 2008 Aug 12;47(32):8283-91. Epub 2008 Jul 18. PMID: 18636748

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).