6MZB:
reference: Cryo-EM structure of phosphodiesterase 6 reveals insights into the allosteric regulation of type I phosphodiesterases., Gulati S, Palczewski K, Engel A, Stahlberg H, Kovacik L, Sci Adv. 2019 Feb 27;5(2):eaav4322. doi: 10.1126/sciadv.aav4322. eCollection 2019, Feb. PMID: 30820458

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