4DQY:
reference: Structural basis for DNA damage-dependent poly(ADP-ribosyl)ation by human PARP-1., Langelier MF, Planck JL, Roy S, Pascal JM, Science. 2012 May 11;336(6082):728-32. PMID: 22582261

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