4MBH:
reference: Penam sulfones and beta-lactamase inhibition: SA2-13 and the importance of the C2 side chain length and composition., Rodkey EA, Winkler ML, Bethel CR, Pagadala SR, Buynak JD, Bonomo RA, van den Akker F, PLoS One. 2014 Jan 16;9(1):e85892. doi: 10.1371/journal.pone.0085892. eCollection, 2014. PMID: 24454944

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