5ETZ:
reference: Crystal Structure of the 11-cis Isomer of Pharaonis Halorhodopsin: Structural Constraints on Interconversions among Different Isomeric States., Chan SK, Kawaguchi H, Kubo H, Murakami M, Ihara K, Maki K, Kouyama T, Biochemistry. 2016 Jul 26;55(29):4092-104. doi: 10.1021/acs.biochem.6b00277. Epub, 2016 Jul 13. PMID: 27352034

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