3O6M

Anti-Tat HIV 11H6H1 Fab' complexed with a 9-mer Tat peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.290 
  • R-Value Work: 0.211 

wwPDB Validation 3D Report Full Report


This is version 1.1 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: 10.1016/j.jmb.2010.10.033
  • Primary Citation of Related Structures:  

  • 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 ...

    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.


    Related Citations: 
    • UV and X-ray structural studies of a 101-residue long Tat protein from a HIV-1 primary isolate and of its mutated, detoxified, vaccine candidate
      Foucault, M.,Mayol, K.,Receveur-Brechot, V.,Bussat, M.C.,Klinguer-Hamour, C.,Verrier, B.,Beck, A.,Haser, R.,Gouet, P.,Guillon, C.
      (2010) Proteins 78: 1441


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
11H6H1 Fab' light chain
L
219N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
11H6H1 Fab' heavy chain
H
219N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Protein Tat 9-mer peptide
C
9Human immunodeficiency virus 1Mutation(s): 0 
Gene Names: tat
Find proteins for Q98XH7 (Human immunodeficiency virus 1)
Go to UniProtKB:  Q98XH7
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.290 
  • R-Value Work: 0.211 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 123.840α = 90.00
b = 69.720β = 109.94
c = 62.160γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
ADSCdata collection
XSCALEdata scaling
AMoREphasing
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-11-10
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance