4GSV:
reference: Structure and function of non-native metal clusters in human arginase I., D'Antonio EL, Hai Y, Christianson DW, Biochemistry. 2012 Oct 23;51(42):8399-409. doi: 10.1021/bi301145n. Epub 2012 Oct , 12. PMID: 23061982

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