4TTM:
reference: Racemic and Quasi-Racemic X-ray Structures of Cyclic Disulfide-Rich Peptide Drug Scaffolds., Wang CK, King GJ, Northfield SE, Ojeda PG, Craik DJ, Angew Chem Int Ed Engl. 2014 Aug 28. doi: 10.1002/anie.201406563. PMID: 25168664

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