4JB2:
reference: The CouPSTU and TarPQM Transporters in Rhodopseudomonas palustris: Redundant, Promiscuous Uptake Systems for Lignin-Derived Aromatic Substrates., Salmon RC, Cliff MJ, Rafferty JB, Kelly DJ, PLoS One. 2013;8(3):e59844. doi: 10.1371/journal.pone.0059844. Epub 2013 Mar 28. PMID: 23555803

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