3W1B:
reference: Structure of the catalytic region of DNA ligase IV in complex with an artemis fragment sheds light on double-strand break repair., Ochi T, Gu X, Blundell TL, Structure. 2013 Apr 2;21(4):672-9. doi: 10.1016/j.str.2013.02.014. Epub 2013 Mar , 21. PMID: 23523427

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