6YPH:
reference: Proposed Allosteric Inhibitors Bind to the ATP Site of CK2alpha., Brear P, Ball D, Stott K, D'Arcy S, Hyvonen M, J Med Chem. 2020 Oct 29. doi: 10.1021/acs.jmedchem.0c01173. PMID: 33119282

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