3ISG:
reference: The 1.4 A Crystal Structure of the Class D beta-Lactamase OXA-1 Complexed with Doripenem., Schneider KD, Karpen ME, Bonomo RA, Leonard DA, Powers RA, Biochemistry. 2009 Nov 24. PMID: 19919101

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