1M64:
reference: Engineering water to act as an active site acid catalyst in a soluble fumarate reductase., Mowat CG, Pankhurst KL, Miles CS, Leys D, Walkinshaw MD, Reid GA, Chapman SK, Biochemistry 2002 Oct 8;41(40):11990-6. PMID: 12356299

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