3H1C:
reference: Crystal structure of Escherichia coli polynucleotide phosphorylase core bound to RNase E, RNA and manganese: implications for catalytic mechanism and RNA degradosome assembly., Nurmohamed S, Vaidialingam B, Callaghan AJ, Luisi BF, J Mol Biol. 2009 May 29;389(1):17-33. Epub 2009 Mar 24. PMID: 19327365

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