2CCM:
reference: Structure of the neuronal protein calexcitin suggests a mode of interaction in signalling pathways of learning and memory., Erskine PT, Beaven GD, Hagan R, Findlow IS, Werner JM, Wood SP, Vernon J, Giese KP, Fox G, Cooper JB, J Mol Biol. 2006 Apr 14;357(5):1536-47. Epub 2006 Feb 8. PMID: 16497326

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