5OXN:
reference: Multispecific Substrate Recognition in a Proton-Dependent Oligopeptide Transporter., Martinez Molledo M, Quistgaard EM, Flayhan A, Pieprzyk J, Low C, Structure. 2018 Mar 6;26(3):467-476.e4. doi: 10.1016/j.str.2018.01.005. Epub 2018, Feb 8. PMID: 29429879

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