4IJ0:
reference: Structures of DNA duplexes containing O6-carboxymethylguanine, a lesion associated with gastrointestinal cancer, reveal a mechanism for inducing pyrimidine transition mutations., Zhang F, Tsunoda M, Suzuki K, Kikuchi Y, Wilkinson O, Millington CL, Margison GP, Williams DM, Czarina Morishita E, Takenaka A, Nucleic Acids Res. 2013 Apr 10. PMID: 23580550

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