1Q78:
reference: Biochemical and structural insights into substrate binding and catalytic mechanism of mammalian poly(A) polymerase., Martin G, Moglich A, Keller W, Doublie S, J Mol Biol 2004 Aug 20;341(4):911-25. PMID: 15328606

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