4JG3:
reference: The Pseudomonas aeruginosa Catabolite Repression Control Protein Crc Is Devoid of RNA Binding Activity., Milojevic T, Grishkovskaya I, Sonnleitner E, Djinovic-Carugo K, Blasi U, PLoS One. 2013 May 23;8(5):e64609. doi: 10.1371/journal.pone.0064609. Print 2013. PMID: 23717639

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