2R1B:
reference: Regulation of Neurexin 1beta Tertiary Structure and Ligand Binding through Alternative Splicing., Shen KC, Kuczynska DA, Wu IJ, Murray BH, Sheckler LR, Rudenko G, Structure. 2008 Mar;16(3):422-31. PMID: 18334217

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