1G90:
reference: Structure of outer membrane protein A transmembrane domain by NMR spectroscopy., Arora A, Abildgaard F, Bushweller JH, Tamm LK, Nat Struct Biol 2001 Apr;8(4):334-8. PMID: 11276254

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