1Z7L:
reference: Crystal structure of a fragment of mouse ubiquitin-activating enzyme., Szczepanowski RH, Filipek R, Bochtler M, J Biol Chem 2005 Jun 10;280(23):22006-11. Epub 2005 Mar 16. PMID: 15774460

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