4LCD:
reference: Mechanism of ubiquitin ligation and lysine prioritization by a HECT E3., Kamadurai HB, Qiu Y, Deng A, Harrison JS, Macdonald C, Actis M, Rodrigues P, Miller DJ, Souphron J, Lewis SM, Kurinov I, Fujii N, Hammel M, Piper R, Kuhlman B, Schulman BA, Elife. 2013 Aug 8;2:e00828. doi: 10.7554/eLife.00828. Print 2013. PMID: 23936628

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