Molecule of the Month: HIV Envelope Glycoprotein
Envelope protein attaches HIV to the cells that it infects and powers fusion of the virus with the cell membrane
Solving the Structure of Env
Exploring the Structure
gp41 and Fusion Inhibitor (PDB entries 2ezo and 3vie)
The gp41 portion of Env glycoprotein gets the virus inside the cell after gp120 attaches to the surface. As with the influenza hemagglutinin protein, a large change in the shape of the protein is thought to drag the viral membrane and cell membrane into close proximity. The formation of a distinctive helical bundle is important in both viruses, as shown on the left in a structure of the extracellular portion of the SIV gp41 protein (PDB entry 2ezo ). Researchers have developed new drugs that target this interaction and mimic part of the helical bundle, blocking the formation of this important structure. The image on the right shows one of these drugs (in green) bound to the inner bundle of gp41 helices (in red), from PDB entry 3vie . To explore these structures in more detail, click on the image for an interactive jmol.
Topics for Further Discussion
- Many structures for fusion-inhibiting drugs are available in the PDB--try searching for "HIV-1 fusion inhibitor."
- Take a look at the EMDataBank to see studies of the whole Env glycoprotein, such as these structures of HIV Env and SIV Env
Related PDB-101 Resources
- Browse Viruses
- Browse HIV and AIDS
- Browse Integrative/Hybrid Methods
- Browse Drug Action
- 4nco: J. P. Julien, A. Cupo, D. Sok, R. L. Stanfield, D. Lyumkis, M. C. Deller, P. J. Klasse, D. R. Burton, R. W. Sanders, J. P. Moore, A. B. Ward & I. A. Wilson (2013) Crystal structure of soluble cleaved HIV-1 envelope trimer. Science epub ahead of print. PMID 24179159.
- 3j5m: D. Lyumkis, J. P. Julien, N. de Val, A. Cupo, C. S. Potter, P. J. Klasse, D. R. Burton, R. W. Sanders, J. P. Moore, B. Carragher, I. A. Wilson & A. B. Ward (2013) Cryo-EM structure of fully glycosylated soluble cleaved HIV-1 envelope trimer. Science 342, 1484-1490.
- 4cc8: A. Bartesaghi, A. Merk, M. J. Borgnia, J. L. S. Milne & S. Subramaniam (2013) Prefusion structure of trimeric HIV-1 envelope glycoprotein determined by cryo-electron microscopy. Nature Structural and Molecular Biology 20, 1352-1357.
- 3vie: X. Yao, H. Chong, C. Zhang, S. Waltersperger, M. Wang, S. Cui & Y. He (2011) Broad antiviral activity and crystal structure of HIV fusion inhibitor sifuvirtide. Journal of Biological Chemistry 287, 6788-6796.
- M. Caffrey (2011) HIV envelope: challenges and opportunities for development of entry inhibitors. Trends in Microbiology 19, 191-197.
- M. A. Checkley, B. G. Luttge & E. O. Freed (2011) HIV-1 envelope glycoprotein biosynthesis, trafficking and incorporation. Journal of Molecular Biology 410, 582- 608.
- 1gc1: C. D. Rizzuto, R. Wyatt, N. Hernandez-Ramos, Y. Sun, P. D. Kwong, W. A. Hendrickson & J. Sodroski (1998) A conserved HIV gp120 glycoprotein structure involved in chemokine receptor binding. Science 280, 1949-1953.
- 2ezo: M. Caffrey, M. Cai, J. Kaufman, S. J. Stahl, P. T. Wingfield, D. G. Covell, A. M. Gronenborn & G. M. Clore (1998) Three-dimensional solution structure of the 44 kDa ectodomain of SIV gp41. EMBO Journal 17, 4572-4584.
January 2014, David Goodselldoi:10.2210/rcsb_pdb/mom_2014_1