4QQU:
reference: The Cobalamin-Independent Methionine Synthase Enzyme Captured in a Substrate-Induced Closed Conformation., Ubhi DK, Robertus JD, J Mol Biol. 2014 Dec 27. pii: S0022-2836(14)00649-4. doi:, 10.1016/j.jmb.2014.12.014. PMID: 25545590

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