4K2E:
reference: Crystal structure of HlyU, the hemolysin gene transcription activator, from Vibrio cholerae N16961 and functional implications., Mukherjee D, Datta AB, Chakrabarti P, Biochim Biophys Acta. 2014 Oct 18;1844(12):2346-2354. doi:, 10.1016/j.bbapap.2014.09.020. PMID: 25450504

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