1MIC:
reference: Solution structure of a parallel left-handed double-helical gramicidin-A determined by 2D 1H NMR., Chen Y, Tucker A, Wallace BA, J Mol Biol 1996 Dec 13;264(4):757-69. PMID: 8980684

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