3K8T:
reference: Structure-Based Design, Synthesis, and Evaluation of 2'-(2-Hydroxyethyl)-2'-deoxyadenosine and the 5'-Diphosphate Derivative as Ribonucleotide Reductase Inhibitors., Sun D, Xu H, Wijerathna SR, Dealwis C, Lee RE, ChemMedChem. 2009 Oct;4(10):1649-56. PMID: 19681093

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