6W5G:
reference: A Surface Loop Modulates Activity of the Bacillus Class D beta-Lactamases., Stewart NK, Bhattacharya M, Toth M, Smith CA, Vakulenko SB, J Struct Biol. 2020 Jun 5:107544. doi: 10.1016/j.jsb.2020.107544. PMID: 32512156

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