Structural highlights
Function
[Q07374_SIVCZ] The envelope glyprotein gp160 precursor down-modulates cell surface CD4 antigen by interacting with it in the endoplasmic reticulum and blocking its transport to the cell surface.[SAAS:SAAS00139820] The gp120-gp41 heterodimer allows rapid transcytosis of the virus through CD4 negative cells such as simple epithelial monolayers of the intestinal, rectal and endocervical epithelial barriers. Both gp120 and gp41 specifically recognize glycosphingolipids galactosyl-ceramide (GalCer) or 3' sulfo-galactosyl-ceramide (GalS) present in the lipid rafts structures of epithelial cells. Binding to these alternative receptors allows the rapid transcytosis of the virus through the epithelial cells. This transcytotic vesicle-mediated transport of virions from the apical side to the basolateral side of the epithelial cells does not involve infection of the cells themselves.[SAAS:SAAS00140087]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
HIV/SIV envelope glycoproteins mediate the first steps in viral infection. They are trimers of a membrane-anchored polypeptide chain, cleaved into two fragments known as gp120 and gp41. The structure of HIV gp120 bound with receptor (CD4) has been known for some time. We have now determined the structure of a fully glycosylated SIV gp120 envelope glycoprotein in an unliganded conformation by X-ray crystallography at 4.0 A resolution. We describe here our experimental and computational approaches, which may be relevant to other resolution-limited crystallographic problems. Key issues were attention to details of beam geometry mandated by small, weakly diffracting crystals, and choice of strategies for phase improvement, starting with two isomorphous derivatives and including multicrystal averaging. We validated the structure by analyzing composite omit maps, averaged among three distinct crystal lattices, and by calculating model-based, SeMet anomalous difference maps. There are at least four ordered sugars on many of the thirteen oligosaccharides.
Determining the structure of an unliganded and fully glycosylated SIV gp120 envelope glycoprotein.,Chen B, Vogan EM, Gong H, Skehel JJ, Wiley DC, Harrison SC Structure. 2005 Feb;13(2):197-211. PMID:15698564[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Chen B, Vogan EM, Gong H, Skehel JJ, Wiley DC, Harrison SC. Determining the structure of an unliganded and fully glycosylated SIV gp120 envelope glycoprotein. Structure. 2005 Feb;13(2):197-211. PMID:15698564 doi:10.1016/j.str.2004.12.004
