3GBP:
reference: Structure of the periplasmic glucose/galactose receptor of Salmonella typhimurium., Mowbray SL, Smith RD, Cole LB, Receptor 1990-91 Winter;1(1-2):41-53. PMID: 1967096

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