3O6L

Anti-Tat HIV 11H6H1 Fab' complexed with a 15-mer Tat peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.188 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Fab'-induced folding of antigenic N-terminal peptides from intrinsically disordered HIV-1 Tat revealed by X-ray crystallography.

Serriere, J.Dugua, J.M.Bossus, M.Verrier, B.Haser, R.Gouet, P.Guillon, C.

(2011) J Mol Biol 405: 33-42

  • DOI: https://doi.org/10.1016/j.jmb.2010.10.033
  • Primary Citation of Related Structures:  
    3O6K, 3O6L, 3O6M

  • PubMed Abstract: 

    Tat, the transcriptional activator protein of human immunodeficiency virus type 1 (HIV-1), is critical for viral replication and is a potential HIV-1 vaccine candidate. This intrinsically disordered protein is present in the extracellular medium and is involved in the pathogenicity of HIV through its interaction with different cellular and viral biological partners. A monoclonal antibody termed 11H6H1, which is specific for the N-terminal region of Tat, was selected for a functional and structural study of the HIV-1 Tat protein. The equilibrium dissociation constants (K(d)) of Tat and Tat fragments complexed with 11H6H1 were estimated by competitive ELISA. Tat contains a single tryptophan residue, Trp11, located in the N-terminal region. We show that the substitution of Trp11 by a phenylalanine completely abolishes the binding of 11H6H1, whereas the transactivating activity of Tat is preserved. The epitope recognized by 11H6H1 was restricted to the 9-mer peptide P(6)KLEPWKHP(14) centered on Trp11. The crystal structures of this 9-mer peptide and of an overlapping 15-mer peptide were determined in complex with Fab' 11H6H1 at 2.4 Å and 2.1 Å resolution, respectively. Tat is intrinsically disordered and can undergo induced folding upon association with a biological partner. Our crystallographic study reveals that the two Tat peptides, which are lodged in the U-shaped groove of the Fab' antigen-binding site, adopt a standard type I β-turn conformation. The central Trp11 that is critical for Fab' recognition is further stabilized by π-stacking interactions. The structural and biological consequences of this induced folding in HIV pathogenesis are discussed.


  • Organizational Affiliation

    Université de Lyon, IFR128 BioSciences Gerland-Lyon Sud, 7 Passage du Vercors, France.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
11H6H1 Fab' light chainA [auth L]219Mus musculusMutation(s): 0 
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
11H6H1 Fab' heavy chainB [auth H]219Mus musculusMutation(s): 0 
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  • Reference Sequence

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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Protein Tat 15-mer peptide15N/AMutation(s): 0 
UniProt
Find proteins for Q98XH7 (Human immunodeficiency virus 1)
Explore Q98XH7 
Go to UniProtKB:  Q98XH7
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UniProt GroupQ98XH7
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.188 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 123.76α = 90
b = 69.03β = 111.4
c = 62.53γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
AMoREphasing
REFMACrefinement
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-11-10
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2023-09-06
    Changes: Data collection, Database references, Refinement description