1XAW:
reference: Structure of the Conserved Cytoplasmic C-terminal Domain of Occludin: Identification of the ZO-1 Binding Surface., Li Y, Fanning AS, Anderson JM, Lavie A, J Mol Biol 2005 Sep 9;352(1):151-64. PMID: 16081103

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