1PYG:
reference: Structural basis for the activation of glycogen phosphorylase b by adenosine monophosphate., Sprang SR, Withers SG, Goldsmith EJ, Fletterick RJ, Madsen NB, Science 1991 Nov 29;254(5036):1367-71. PMID: 1962195

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