1U1L:
reference: Human UP1 as a Model for Understanding Purine Recognition in the Family of Proteins Containing the RNA Recognition Motif (RRM)., Myers JC, Shamoo Y, J Mol Biol 2004 Sep 17;342(3):743-56. PMID: 15342234

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