| 2RKM: reference: Peptide binding in OppA, the crystal structures of the periplasmic oligopeptide binding protein in the unliganded form and in complex with lysyllysine., Sleigh SH, Tame JR, Dodson EJ, Wilkinson AJ, Biochemistry 1997 Aug 12;36(32):9747-58. PMID: 9245406 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).