2C5U:
reference: Molecular architecture and ligand recognition determinants for T4 RNA ligase., El Omari K, Ren J, Bird LE, Bona MK, Klarmann G, LeGrice SF, Stammers DK, J Biol Chem. 2006 Jan 20;281(3):1573-9. Epub 2005 Nov 1. PMID: 16263720

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