2AXB:
reference: Stabilizing contributions of sulfur-modified nucleotides: crystal structure of a DNA duplex with 2'-O-[2-(methoxy)ethyl]-2-thiothymidines., Diop-Frimpong B, Prakash TP, Rajeev KG, Manoharan M, Egli M, Nucleic Acids Res 2005 Sep 16;33(16):5297-307. Print 2005. PMID: 16170156

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