5EXD:
reference: One-carbon chemistry of oxalate oxidoreductase captured by X-ray crystallography., Gibson MI, Chen PY, Johnson AC, Pierce E, Can M, Ragsdale SW, Drennan CL, Proc Natl Acad Sci U S A. 2015 Dec 28. pii: 201518537. PMID: 26712008

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