1OLC:
reference: The crystal structures of the oligopeptide-binding protein OppA complexed with tripeptide and tetrapeptide ligands., Tame JR, Dodson EJ, Murshudov G, Higgins CF, Wilkinson AJ, Structure 1995 Dec 15;3(12):1395-406. PMID: 8747465

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