1TKQ:
reference: An asymmetric ion channel derived from gramicidin A. Synthesis, function and NMR structure., Xie X, Al-Momani L, Reiss P, Griesinger C, Koert U, FEBS J 2005 Feb;272(4):975-86. PMID: 15691331

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