4CDJ:
reference: Structures of Wnt-Antagonist ZNRF3 and Its Complex with R-Spondin 1 and Implications for Signaling., Peng WC, de Lau W, Madoori PK, Forneris F, Granneman JC, Clevers H, Gros P, PLoS One. 2013 Dec 12;8(12):e83110. doi: 10.1371/journal.pone.0083110. PMID: 24349440

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