5AWN image
Entry Detail
PDB ID:
5AWN
Keywords:
Title:
Crystal structure of Human anti-HIV-1 broadly neutralizing antibody 3BC176 Fab
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2015-07-06
Release Date:
2015-11-11
Method Details:
Experimental Method:
Resolution:
1.89 Å
R-Value Free:
0.22
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Heavy chain of 3BC176 Fab
Chain IDs:A (auth: H)
Chain Length:232
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Light chain of 3BC176 Fab
Mutations:G108R, N112A, T114S
Chain IDs:B (auth: L)
Chain Length:216
Number of Molecules:1
Biological Source:Homo sapiens
Primary Citation
Antibodies to a conformational epitope on gp41 neutralize HIV-1 by destabilizing the Env spike.
Nat Commun 6 8167 8167 (2015)
PMID: 26404402 DOI: 10.1038/ncomms9167

Abstact

The recent identification of three broadly neutralizing antibodies (bnAbs) against gp120-gp41 interface epitopes has expanded the targetable surface on the HIV-1 envelope glycoprotein (Env) trimer. By using biochemical, biophysical and computational methods, we map the previously unknown trimer epitopes of two related antibodies, 3BC315 and 3BC176. A cryo-EM reconstruction of a soluble Env trimer bound to 3BC315 Fab at 9.3 Å resolution reveals that the antibody binds between two gp41 protomers, and neutralizes the virus by accelerating trimer decay. In contrast, bnAb 35O22 binding to a partially overlapping quaternary epitope at the gp120-gp41 interface does not induce decay. A conserved gp41-proximal glycan at N88 was also shown to play a role in the binding kinetics of 3BC176 and 3BC315. Finally, our data suggest that the dynamic structure of the Env trimer influences exposure of bnAb epitopes.

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Primary Citation of related structures