3G9R:
reference: Structure of the HIV-1 gp41 Membrane-Proximal Ectodomain Region in a Putative Prefusion Conformation., Lu M, Liu J, Deng Y, Dey A, Moore J, Biochemistry. 2009 Feb 18. PMID: 19226163

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