3FN0:
reference: A conformational switch in HIV gp41 revealed by the structures of overlapping epitopes recognized by neutralizing antibodies., Pejchal R, Gach JS, Brunel FM, Cardoso RM, Stanfield RL, Dawson PE, Burton DR, Zwick MB, Wilson IA, J Virol. 2009 Jun 10. PMID: 19515770

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