4HW5:
reference: Human C3a and C3a desArg anaphylatoxins have conserved structures, in contrast to C5a and C5a desArg., Bajic G, Yatime L, Klos A, Andersen GR, Protein Sci. 2012 Nov 26. doi: 10.1002/pro.2200. PMID: 23184394

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