3LTU:
reference: Hydrogen bond formation between the naturally modified nucleobase and phosphate backbone., Sheng J, Zhang W, Hassan AE, Gan J, Soares AS, Geng S, Ren Y, Huang Z, Nucleic Acids Res. 2012 May 28. PMID: 22641848

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