1FNK:
reference: A strategically positioned cation is crucial for efficient catalysis by chorismate mutase., Kast P, Grisostomi C, Chen IA, Li S, Krengel U, Xue Y, Hilvert D, J Biol Chem 2000 Nov 24;275(47):36832-8. PMID: 10960481

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