4MD7:
reference: Active Form of the Protein Kinase CK2 alphabeta Holoenzyme Is a Strong Complex with Symmetric Architecture., Lolli G, Ranchio A, Battistutta R, ACS Chem Biol. 2013 Nov 11. PMID: 24175891

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