4X6T:
reference: Inhibiting the beta-Lactamase of Mycobacterium tuberculosis (Mtb) with Novel Boronic Acid Transition-State Inhibitors (BATSIs)., Kurz SG, Hazra S, Bethel CR, Romagnoli C, Caselli E, Prati F, Blanchard JS, Bonomo RA, ACS Infect Dis. 2015 Jun 12;1(6):234-42. doi: 10.1021/acsinfecdis.5b00003. Epub, 2015 Apr 15. PMID: 27622739

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