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Access through your institution Buy or subscribe In the first study, Ozorowski, Pallesen _et al_. used cryo-electron microscopy (cryo-EM) to investigate conformational changes in the Env
glycoprotein (composed of three gp120 and three gp41 subunits) that occur after HIV-1 binding and might drive fusion. They compared cryo-EM maps of a fully glycosylated SOSIP (a solubilized
and stabilized version of the Env trimer) in complex with CD4 and antibodies that recognize the co-receptor-binding site with pre-fusion SOSIP trimers, and report receptor-induced structural
rearrangements in Env. These conformational changes affected both the surface gp120 subunits and the transmembrane gp41 subunits, and included changes to the V1/V2 and V3 loops, the
formation of a helix and a large rearrangement of the gp41 fusion peptide following receptor binding into a newly formed pocket. The repositioned fusion peptide was found to be stabilized by
many newly formed interactions within Env itself, which, when mutated, resulted in decreased viral infectivity. The authors hypothesize that these molecular rearrangements result in the
formation of a stable fusion intermediate and prime the viral glycoprotein for further transitions that occur following co-receptor binding. > new insights into the receptor-mediated
fusion stage of HIV-1 entry This is a preview of subscription content, access via your institution ACCESS OPTIONS Access through your institution Access Nature and 54 other Nature Portfolio
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during checkout ADDITIONAL ACCESS OPTIONS: * Log in * Learn about institutional subscriptions * Read our FAQs * Contact customer support REFERENCES * Ozorowski, G., Pallesen, J. et al. Open
and closed structures reveal allostery and pliability in the HIV-1 envelope spike. _Nature_ http://dx.doi.org/10.1038/nature23010 (2017) * Zaitseva, E. et al. Fusion stage of HIV-1 entry
depends on virus-induced cell surface exposure of phosphatidylserine. _Cell Host Microbe_ 22, 99–110.e7 (2017) Article CAS PubMed PubMed Central Google Scholar Download references
Authors * Ashley York View author publications You can also search for this author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS
ARTICLE York, A. When two become one. _Nat Rev Microbiol_ 15, 511 (2017). https://doi.org/10.1038/nrmicro.2017.85 Download citation * Published: 24 July 2017 * Issue Date: September 2017 *
DOI: https://doi.org/10.1038/nrmicro.2017.85 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get shareable link Sorry, a shareable link is not
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