3HBU:
reference: Metzincin's canonical methionine is responsible for the structural integrity of the zinc-binding site., Oberholzer AE, Bumann M, Hege T, Russo S, Baumann U, Biol Chem. 2009 Jun 27. PMID: 19558324

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