2P9V:
reference: O-Aryloxycarbonyl Hydroxamates: New beta-Lactamase Inhibitors That Cross-Link the Active Site., Wyrembak PN, Babaoglu K, Pelto RB, Shoichet BK, Pratt RF, J Am Chem Soc. 2007 Aug 8;129(31):9548-9. Epub 2007 Jul 12. PMID: 17628063

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