2Y7C:
reference: The structure of M.EcoKI Type I DNA methyltransferase with a DNA mimic antirestriction protein., Kennaway CK, Obarska-Kosinska A, White JH, Tuszynska I, Cooper LP, Bujnicki JM, Trinick J, Dryden DT, Nucleic Acids Res. 2009 Feb;37(3):762-70. Epub 2008 Dec 11. PMID: 19074193

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