6GPB:
reference: Refined crystal structure of the phosphorylase-heptulose 2-phosphate-oligosaccharide-AMP complex., Johnson LN, Acharya KR, Jordan MD, McLaughlin PJ, J Mol Biol 1990 Feb 5;211(3):645-61. PMID: 2106586

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