2C4J:
reference: Alternative mutations of a positively selected residue elicit gain or loss of functionalities in enzyme evolution., Norrgard MA, Ivarsson Y, Tars K, Mannervik B, Proc Natl Acad Sci U S A. 2006 Mar 28;103(13):4876-81. Epub 2006 Mar 20. PMID: 16549767

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