2VOK:
reference: TRIM21 is an IgG receptor that is structurally, thermodynamically, and kinetically conserved., Keeble AH, Khan Z, Forster A, James LC, Proc Natl Acad Sci U S A. 2008 Apr 22;105(16):6045-50. Epub 2008 Apr 17. PMID: 18420815

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