1JEK:
reference: The trimer-of-hairpins motif in membrane fusion: Visna virus., Malashkevich VN, Singh M, Kim PS, Proc Natl Acad Sci U S A 2001 Jul 17;98(15):8502-6. PMID: 11447278

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