4DYJ:
reference: Crystal structures of lysine-preferred racemases, the non-antibiotic selectable markers for transgenic plants., Wu HM, Kuan YC, Chu CH, Hsu WH, Wang WC, PLoS One. 2012;7(10):e48301. doi: 10.1371/journal.pone.0048301. Epub 2012 Oct 31. PMID: 23118975

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