2CIU:
reference: The Tim21 binding domain connects the preprotein translocases of both mitochondrial membranes., Albrecht R, Rehling P, Chacinska A, Brix J, Cadamuro SA, Volkmer R, Guiard B, Pfanner N, Zeth K, EMBO Rep. 2006 Dec;7(12):1233-8. Epub 2006 Nov 10. PMID: 17099692

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