7ugq: Difference between revisions

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== Structural highlights ==
== Structural highlights ==
<table><tr><td colspan='2'>[[7ugq]] is a 18 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Human_immunodeficiency_virus_1 Human immunodeficiency virus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7UGQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7UGQ FirstGlance]. <br>
<table><tr><td colspan='2'>[[7ugq]] is a 18 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Human_immunodeficiency_virus_1 Human immunodeficiency virus 1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7UGQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7UGQ FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7ugq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7ugq OCA], [https://pdbe.org/7ugq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7ugq RCSB], [https://www.ebi.ac.uk/pdbsum/7ugq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7ugq ProSAT]</span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7ugq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7ugq OCA], [https://pdbe.org/7ugq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7ugq RCSB], [https://www.ebi.ac.uk/pdbsum/7ugq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7ugq ProSAT]</span></td></tr>
</table>
</table>
== Function ==
[https://www.uniprot.org/uniprot/D7S1H2_9HIV1 D7S1H2_9HIV1] Envelope glycoprotein gp160: Oligomerizes in the host endoplasmic reticulum into predominantly trimers. In a second time, gp160 transits in the host Golgi, where glycosylation is completed. The precursor is then proteolytically cleaved in the trans-Golgi and thereby activated by cellular furin or furin-like proteases to produce gp120 and gp41.[HAMAP-Rule:MF_04083]  Surface protein gp120: Attaches the virus to the host lymphoid cell by binding to the primary receptor CD4. This interaction induces a structural rearrangement creating a high affinity binding site for a chemokine coreceptor like CXCR4 and/or CCR5. Acts as a ligand for CD209/DC-SIGN and CLEC4M/DC-SIGNR, which are respectively found on dendritic cells (DCs), and on endothelial cells of liver sinusoids and lymph node sinuses. These interactions allow capture of viral particles at mucosal surfaces by these cells and subsequent transmission to permissive cells. HIV subverts the migration properties of dendritic cells to gain access to CD4+ T-cells in lymph nodes. Virus transmission to permissive T-cells occurs either in trans (without DCs infection, through viral capture and transmission), or in cis (following DCs productive infection, through the usual CD4-gp120 interaction), thereby inducing a robust infection. In trans infection, bound virions remain infectious over days and it is proposed that they are not degraded, but protected in non-lysosomal acidic organelles within the DCs close to the cell membrane thus contributing to the viral infectious potential during DCs' migration from the periphery to the lymphoid tissues. On arrival at lymphoid tissues, intact virions recycle back to DCs' cell surface allowing virus transmission to CD4+ T-cells.[HAMAP-Rule:MF_04083]  Transmembrane protein gp41: Acts as a class I viral fusion protein. Under the current model, the protein has at least 3 conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During fusion of viral and target intracellular membranes, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes. Complete fusion occurs in host cell endosomes and is dynamin-dependent, however some lipid transfer might occur at the plasma membrane. The virus undergoes clathrin-dependent internalization long before endosomal fusion, thus minimizing the surface exposure of conserved viral epitopes during fusion and reducing the efficacy of inhibitors targeting these epitopes. Membranes fusion leads to delivery of the nucleocapsid into the cytoplasm.[HAMAP-Rule:MF_04083]
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== Publication Abstract from PubMed ==
== Publication Abstract from PubMed ==
BG24, a VRC01-class broadly neutralizing antibody (bNAb) against HIV-1 Env with relatively few somatic hypermutations (SHMs), represents a promising target for vaccine strategies to elicit CD4-binding site (CD4bs) bNAbs. To understand how SHMs correlate with BG24 neutralization of HIV-1, we report 4.1 A and 3.4 A single-particle cryo-EM structures of two inferred germline (iGL) BG24 precursors complexed with engineered Env-based immunogens lacking CD4bs N-glycans. Structures reveal critical Env contacts by BG24iGL and identify antibody light chain structural features that impede Env recognition. In addition, biochemical data and cryo-EM structures of BG24iGL variants bound to Envs with CD4bs glycans present provide insights into N-glycan accommodation, including structural modes of light chain adaptations in the presence of the N276gp120 glycan. Together, these findings reveal Env regions critical for germline antibody recognition and potential sites to alter in immunogen design.
BG24, a VRC01-class broadly neutralizing antibody (bNAb) against HIV-1 Env with relatively few somatic hypermutations (SHMs), represents a promising target for vaccine strategies to elicit CD4-binding site (CD4bs) bNAbs. To understand how SHMs correlate with BG24 neutralization of HIV-1, we report 4.1 A and 3.4 A single-particle cryo-EM structures of two inferred germline (iGL) BG24 precursors complexed with engineered Env-based immunogens lacking CD4bs N-glycans. Structures reveal critical Env contacts by BG24(iGL) and identify antibody light chain structural features that impede Env recognition. In addition, biochemical data and cryo-EM structures of BG24(iGL) variants bound to Envs with CD4bs glycans present provide insights into N-glycan accommodation, including structural modes of light chain adaptations in the presence of the N276(gp120) glycan. Together, these findings reveal Env regions critical for germline antibody recognition and potential sites to alter in immunogen design.


HIV-1 CD4-binding site germline antibody-Env structures inform vaccine design.,Dam KA, Barnes CO, Gristick HB, Schoofs T, Gnanapragasam PNP, Nussenzweig MC, Bjorkman PJ Nat Commun. 2022 Oct 17;13(1):6123. doi: 10.1038/s41467-022-33860-2. PMID:36253376<ref>PMID:36253376</ref>
HIV-1 CD4-binding site germline antibody-Env structures inform vaccine design.,Dam KA, Barnes CO, Gristick HB, Schoofs T, Gnanapragasam PNP, Nussenzweig MC, Bjorkman PJ Nat Commun. 2022 Oct 17;13(1):6123. doi: 10.1038/s41467-022-33860-2. PMID:36253376<ref>PMID:36253376</ref>
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==See Also==
*[[Gp120 3D structures|Gp120 3D structures]]
*[[Gp41 3D Structures|Gp41 3D Structures]]
== References ==
== References ==
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