3PIK:
reference: Crystal Structure of Escherichia coli CusC, the Outer Membrane Component of a Heavy Metal Efflux Pump., Kulathila R, Kulathila R, Indic M, van den Berg B, PLoS One. 2011 Jan 7;6(1):e15610. PMID: 21249122

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