2HR1:
reference: The Role of Arg165 Towards Base Flipping, Base Stabilization and Catalysis in M.HhaI., Shieh FK, Youngblood B, Reich NO, J Mol Biol. 2006 Sep 22;362(3):516-27. Epub 2006 Jul 22. PMID: 16926025

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