1U2C:
reference: The structure of the N-terminal region of murine skeletal muscle alpha-dystroglycan discloses a modular architecture., Bozic D, Sciandra F, Lamba D, Brancaccio A, J Biol Chem 2004 Oct 22;279(43):44812-6. Epub 2004 Aug 23. PMID: 15326183

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