4BCW:
reference: Sulfocoumarins (1,2-Benzoxathiine-2,2-dioxides): A Class of Potent and Isoform-Selective Inhibitors of Tumor-Associated Carbonic Anhydrases., Tars K, Vullo D, Kazaks A, Leitans J, Lends A, Grandane A, Zalubovskis R, Scozzafava A, Supuran CT, J Med Chem. 2013 Jan 10;56(1):293-300. doi: 10.1021/jm301625s. Epub 2012 Dec 27. PMID: 23241068

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