4AXK:
reference: Evolution of substrate specificity in a recipient's enzyme following horizontal gene transfer., Noda-Garcia L, Camacho-Zarco AR, Medina-Ruiz S, Gaytan P, Carrillo-Tripp M, Fulop V, Barona-Gomez F, Mol Biol Evol. 2013 Sep;30(9):2024-34. doi: 10.1093/molbev/mst115. Epub 2013 Jun , 25. PMID: 23800623

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