4PV1:
reference: Traffic within the cytochrome b6f lipoprotein complex: gating of the quinone portal., Hasan SS, Proctor EA, Yamashita E, Dokholyan NV, Cramer WA, Biophys J. 2014 Oct 7;107(7):1620-8. doi: 10.1016/j.bpj.2014.08.003. PMID: 25296314

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