1JL4

CRYSTAL STRUCTURE OF THE HUMAN CD4 N-TERMINAL TWO DOMAIN FRAGMENT COMPLEXED TO A CLASS II MHC MOLECULE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.3 Å
  • R-Value Free: 0.453 
  • R-Value Work: 0.420 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal structure of the human CD4 N-terminal two-domain fragment complexed to a class II MHC molecule.

Wang, J.H.Meijers, R.Xiong, Y.Liu, J.H.Sakihama, T.Zhang, R.Joachimiak, A.Reinherz, E.L.

(2001) Proc.Natl.Acad.Sci.USA 98: 10799-10804

  • DOI: 10.1073/pnas.191124098

  • PubMed Abstract: 
  • The structural basis of the interaction between the CD4 coreceptor and a class II major histocompatibility complex (MHC) is described. The crystal structure of a complex containing the human CD4 N-terminal two-domain fragment and the murine I-A(k) cl ...

    The structural basis of the interaction between the CD4 coreceptor and a class II major histocompatibility complex (MHC) is described. The crystal structure of a complex containing the human CD4 N-terminal two-domain fragment and the murine I-A(k) class II MHC molecule with associated peptide (pMHCII) shows that only the "top corner" of the CD4 molecule directly contacts pMHCII. The CD4 Phe-43 side chain extends into a hydrophobic concavity formed by MHC residues from both alpha 2 and beta 2 domains. A ternary model of the CD4-pMHCII-T-cell receptor (TCR) reveals that the complex appears V-shaped with the membrane-proximal pMHCII at the apex. This configuration excludes a direct TCR-CD4 interaction and suggests how TCR and CD4 signaling is coordinated around the antigenic pMHCII complex. Human CD4 binds to HIV gp120 in a manner strikingly similar to the way in which CD4 interacts with pMHCII. Additional contacts between gp120 and CD4 give the CD4-gp120 complex a greater affinity. Thus, ligation of the viral envelope glycoprotein to CD4 occludes the pMHCII-binding site on CD4, contributing to immunodeficiency.


    Organizational Affiliation

    Laboratory of Immunobiology and Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA. jwang@dfci.harvard.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
H-2 CLASS II HISTOCOMPATIBILITY ANTIGEN, A-K ALPHA CHAIN
A
178Mus musculusMutation(s): 0 
Gene Names: H2-Aa
Find proteins for P01910 (Mus musculus)
Go to UniProtKB:  P01910
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
H-2 CLASS II HISTOCOMPATIBILITY ANTIGEN, A-K BETA CHAIN
B
185Mus musculusMutation(s): 0 
Gene Names: H2-Ab1
Find proteins for P06343 (Mus musculus)
Go to UniProtKB:  P06343
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
OVOTRANSFERRIN
C
16Gallus gallusMutation(s): 0 
Find proteins for P02789 (Gallus gallus)
Go to UniProtKB:  P02789
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
T-CELL SURFACE GLYCOPROTEIN CD4
D
178Homo sapiensMutation(s): 0 
Gene Names: CD4
Find proteins for P01730 (Homo sapiens)
Go to Gene View: CD4
Go to UniProtKB:  P01730
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 4.3 Å
  • R-Value Free: 0.453 
  • R-Value Work: 0.420 
  • Space Group: P 43 2 2
Unit Cell:
Length (Å)Angle (°)
a = 145.195α = 90.00
b = 145.195β = 90.00
c = 103.846γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
FFFEARmodel building
FFFEARphasing
SCALEPACKdata scaling
AMoREphasing
DENZOdata reduction
EPMRphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-09-19
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Refinement description