4F1R:
reference: Structure analysis of the global metabolic regulator Crc from Pseudomonas aeruginosa., Wei Y, Zhang H, Gao ZQ, Xu JH, Liu QS, Dong YH, IUBMB Life. 2013 Jan;65(1):50-7. doi: 10.1002/iub.1103. PMID: 23281037

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