2VDW:
reference: Structural insights into the mechanism and evolution of the vaccinia virus mRNA cap N7 methyl-transferase., De la Pena M, Kyrieleis OJ, Cusack S, EMBO J. 2007 Nov 28;26(23):4913-25. Epub 2007 Nov 8. PMID: 17989694

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