3TGQ

Crystal structure of unliganded HIV-1 clade B strain YU2 gp120 core


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.40 Å
  • R-Value Free: 0.313 
  • R-Value Work: 0.280 
  • R-Value Observed: 0.281 

Starting Model: experimental
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This is version 1.5 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 YU2 gp120
A, B, C, D
352Human immunodeficiency virus 1Mutation(s): 0 
Gene Names: HIV-1 env
UniProt
Find proteins for P35961 (Human immunodeficiency virus type 1 group M subtype B (isolate YU-2))
Explore P35961 
Go to UniProtKB:  P35961
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP35961
Glycosylation
Glycosylation Sites: 6
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
AA [auth D]
BA [auth D]
CA [auth D]
E [auth A]
F [auth A]
AA [auth D],
BA [auth D],
CA [auth D],
E [auth A],
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A],
L [auth A],
M [auth A],
N [auth B],
O [auth B],
P [auth B],
Q [auth B],
R [auth B],
S [auth B],
T [auth C],
U [auth C],
V [auth C],
W [auth C],
X [auth C],
Y [auth C],
Z [auth D]
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.40 Å
  • R-Value Free: 0.313 
  • R-Value Work: 0.280 
  • R-Value Observed: 0.281 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 222.97α = 90
b = 222.97β = 90
c = 86.48γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

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: 2014-04-02
    Changes: Source and taxonomy
  • Version 1.3: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Data collection, Derived calculations, Structure summary
  • Version 1.4: 2023-09-13
    Changes: Advisory, Data collection, Database references, Refinement description, Structure summary
  • Version 1.5: 2024-10-16
    Changes: Structure summary