2GBP:
reference: Sugar and signal-transducer binding sites of the Escherichia coli galactose chemoreceptor protein., Vyas NK, Vyas MN, Quiocho FA, Science 1988 Dec 2;242(4883):1290-5. PMID: 3057628

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