3F87:
reference: An alpha/beta-Peptide Helix Bundle with a Pure beta(3)-Amino Acid Core and a Distinctive Quaternary Structure., Giuliano MW, Horne WS, Gellman SH, J Am Chem Soc. 2009 Jul 6. PMID: 19580264

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