3DBA:
reference: The Structure of the GAF A Domain from Phosphodiesterase 6C Reveals Determinants of cGMP Binding, a Conserved Binding Surface, and a Large cGMP-dependent Conformational Change., Martinez SE, Heikaus CC, Klevit RE, Beavo JA, J Biol Chem. 2008 Sep 19;283(38):25913-9. Epub 2008 Jul 9. PMID: 18614542

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