2KAA:
reference: Solution structure of hirsutellin A--new insights into the active site and interacting interfaces of ribotoxins., Viegas A, Herrero-Galan E, Onaderra M, Macedo AL, Bruix M, FEBS J. 2009 Apr;276(8):2381-90. PMID: 19348010

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