2CGP:
reference: The structure of a CAP-DNA complex having two cAMP molecules bound to each monomer., Passner JM, Steitz TA, Proc Natl Acad Sci U S A 1997 Apr 1;94(7):2843-7. PMID: 9096308

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