1DAY:
reference: GTP plus water mimic ATP in the active site of protein kinase CK2., Niefind K, Putter M, Guerra B, Issinger OG, Schomburg D, Nat Struct Biol 1999 Dec;6(12):1100-3. PMID: 10581548

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