4HHG:
reference: Electron Flow through Nitrotyrosinate in Pseudomonas aeruginosa Azurin., Warren JJ, Herrera N, Hill MG, Winkler JR, Gray HB, J Am Chem Soc. 2013 Jul 16. PMID: 23859602

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