3TGT

Crystal structure of unliganded HIV-1 clade A/E strain 93TH057 gp120 core


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.191 

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This is version 1.3 of the entry. See complete history


Literature

Unliganded HIV-1 gp120 core structures assume the CD4-bound conformation with regulation by quaternary interactions and variable loops.

Kwon, Y.D.Finzi, A.Wu, X.Dogo-Isonagie, C.Lee, L.K.Moore, L.R.Schmidt, S.D.Stuckey, J.Yang, Y.Zhou, T.Zhu, J.Vicic, D.A.Debnath, A.K.Shapiro, L.Bewley, C.A.Mascola, J.R.Sodroski, J.G.Kwong, P.D.

(2012) Proc Natl Acad Sci U S A 109: 5663-5668

  • DOI: https://doi.org/10.1073/pnas.1112391109
  • Primary Citation of Related Structures:  
    3TGQ, 3TGR, 3TGS, 3TGT, 3TIH

  • PubMed Abstract: 

    The HIV-1 envelope (Env) spike (gp120(3)/gp41(3)) undergoes considerable structural rearrangements to mediate virus entry into cells and to evade the host immune response. Engagement of CD4, the primary human receptor, fixes a particular conformation and primes Env for entry. The CD4-bound state, however, is prone to spontaneous inactivation and susceptible to antibody neutralization. How does unliganded HIV-1 maintain CD4-binding capacity and regulate transitions to the CD4-bound state? To define this mechanistically, we determined crystal structures of unliganded core gp120 from HIV-1 clades B, C, and E. Notably, all of these unliganded HIV-1 structures resembled the CD4-bound state. Conformational fixation with ligand selection and thermodynamic analysis of full-length and core gp120 interactions revealed that the tendency of HIV-1 gp120 to adopt the CD4-bound conformation was restrained by the V1/V2- and V3-variable loops. In parallel, we determined the structure of core gp120 in complex with the small molecule, NBD-556, which specifically recognizes the CD4-bound conformation of gp120. Neutralization by NBD-556 indicated that Env spikes on primary isolates rarely assume the CD4-bound conformation spontaneously, although they could do so when quaternary restraints were loosened. Together, the results suggest that the CD4-bound conformation represents a "ground state" for the gp120 core, with variable loop and quaternary interactions restraining unliganded gp120 from "snapping" into this conformation. A mechanism of control involving deformations in unliganded structure from a functionally critical state (e.g., the CD4-bound state) provides advantages in terms of HIV-1 Env structural diversity and resistance to antibodies and inhibitors, while maintaining elements essential for entry.


  • Organizational Affiliation

    Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
HIV-1 clade A/E 93TH057 gp120353Human immunodeficiency virus 1Mutation(s): 0 
Gene Names: HIV-1 env
UniProt
Find proteins for Q0ED31 (Human immunodeficiency virus 1)
Explore Q0ED31 
Go to UniProtKB:  Q0ED31
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ0ED31
Glycosylation
Glycosylation Sites: 10
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

Download Ideal Coordinates CCD File 
L [auth A]4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N
NAG
Query on NAG

Download Ideal Coordinates CCD File 
B [auth A]
C [auth A]
D [auth A]
E [auth A]
F [auth A]
B [auth A],
C [auth A],
D [auth A],
E [auth A],
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A]
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.191 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 63.556α = 90
b = 66.944β = 90
c = 88.029γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-04-04
    Type: Initial release
  • Version 1.1: 2012-05-23
    Changes: Database references
  • Version 1.2: 2017-11-08
    Changes: Refinement description
  • Version 1.3: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Data collection, Derived calculations, Structure summary