1GTC:
reference: Structural variation among retroviral primer-DNA junctions: solution structure of the HIV-1 (-)-strand Okazaki fragment r(gcca)d(CTGC).d(GCAGTGGC)., Fedoroff OYu, Salazar M, Reid BR, Biochemistry 1996 Aug 27;35(34):11070-80. PMID: 8780509

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