6e5p
Backbone model based on cryo-EM map at 8.5 A of domain-swapped, glycan-reactive, neutralizing antibody 2G12 bound to HIV-1 Env BG505 DS-SOSIP, which was also bound to CD4-binding site antibody VRC03Backbone model based on cryo-EM map at 8.5 A of domain-swapped, glycan-reactive, neutralizing antibody 2G12 bound to HIV-1 Env BG505 DS-SOSIP, which was also bound to CD4-binding site antibody VRC03
Structural highlights
Function[Q2N0S6_9HIV1] 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 (By similarity).[RuleBase:RU004292][SAAS:SAAS000328_004_020447] 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 (By similarity).[SAAS:SAAS000328_004_240990] Publication Abstract from PubMedOver the past decade, structures have been determined for broadly neutralizing antibodies that recognize all major exposed surfaces of the prefusion-closed HIV-1-envelope (Env) trimer. To understand this recognition and its implications, we analyzed 206 antibody-HIV-1 Env structures from the Protein Data Bank with resolution suitable to define interaction chemistries and measured antibody neutralization on a 208-strain panel. Those with >25% breadth segregated into almost two dozen classes based on ontogeny and recognition and into six epitope categories based on recognized Env residues. For paratope, the number of protruding loops and level of somatic hypermutation were significantly higher for broad HIV-1 neutralizing antibodies than for a comparison set of non-HIV-1 antibodies (p < 0.0001). For epitope, the number of independent sequence segments was higher (p < 0.0001), as well as the glycan component surface area (p = 0.0005). The unusual characteristics of epitope and paratope delineated here are likely to reflect respectively virus-immune evasion and antibody-recognition solutions that allow effective neutralization of HIV-1. Structural Survey of Broadly Neutralizing Antibodies Targeting the HIV-1 Env Trimer Delineates Epitope Categories and Characteristics of Recognition.,Chuang GY, Zhou J, Acharya P, Rawi R, Shen CH, Sheng Z, Zhang B, Zhou T, Bailer RT, Dandey VP, Doria-Rose NA, Louder MK, McKee K, Mascola JR, Shapiro L, Kwong PD Structure. 2019 Jan 2;27(1):196-206.e6. doi: 10.1016/j.str.2018.10.007. Epub 2018, Nov 21. PMID:30471922[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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