1NHC:
reference: Structural insights into the processivity of endopolygalacturonase I from Aspergillus niger., van Pouderoyen G, Snijder HJ, Benen JA, Dijkstra BW, FEBS Lett 2003 Nov 20;554(3):462-6. PMID: 14623112

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