5D2C:
reference: Imidazole as a Small Molecule Analogue in Two-Component Signal Transduction., Page SC, Silversmith RE, Collins EJ, Bourret RB, Biochemistry. 2015 Dec 15;54(49):7248-60. doi: 10.1021/acs.biochem.5b01082. Epub , 2015 Dec 2. PMID: 26569142

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