1YJD:
reference: Crystal structure of a soluble CD28-Fab complex., Evans EJ, Esnouf RM, Manso-Sancho R, Gilbert RJ, James JR, Yu C, Fennelly JA, Vowles C, Hanke T, Walse B, Hunig T, Sorensen P, Stuart DI, Davis SJ, Nat Immunol 2005 Mar;6(3):271-9. Epub 2005 Feb 6. PMID: 15696168

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