4GEC:
reference: Crystal Structures of E. coli Native MenH and Two Active Site Mutants., Johnston JM, Jiang M, Guo Z, Baker EN, PLoS One. 2013 Apr 18;8(4):e61325. doi: 10.1371/journal.pone.0061325. Print 2013. PMID: 23637813

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