3FTM:
reference: Structure-guided engineering of the regioselectivity of RNA ligase ribozymes., Pitt JN, Ferre-D'Amare AR, J Am Chem Soc. 2009 Mar 18;131(10):3532-40. PMID: 19220054

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