3S4S

Crystal structure of CD4 mutant bound to HLA-DR1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.251 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Affinity maturation of human CD4 by yeast surface display and crystal structure of a CD4-HLA-DR1 complex.

Wang, X.X.Li, Y.Yin, Y.Mo, M.Wang, Q.Gao, W.Wang, L.Mariuzza, R.A.

(2011) Proc.Natl.Acad.Sci.USA 108: 15960-15965

  • DOI: 10.1073/pnas.1109438108
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Helper T-cell activation generally requires the coreceptor CD4, which binds MHC class II molecules. A remarkable feature of the CD4-MHC class II interaction is its exceptionally low affinity, which ranges from K(D) = ∼200 μM to >2 mM. Investigating t ...

    Helper T-cell activation generally requires the coreceptor CD4, which binds MHC class II molecules. A remarkable feature of the CD4-MHC class II interaction is its exceptionally low affinity, which ranges from K(D) = ∼200 μM to >2 mM. Investigating the biological role of the much lower affinity of this interaction than those of other cell-cell recognition molecules will require CD4 mutants with enhanced binding to MHC class II for testing in models of T-cell development. To this end, we used in vitro-directed evolution to increase the affinity of human CD4 for HLA-DR1. A mutant CD4 library was displayed on the surface of yeast and selected using HLA-DR1 tetramers or monomers, resulting in isolation of a CD4 clone containing 11 mutations. Reversion mutagenesis showed that most of the affinity increase derived from just two substitutions, Gln40Tyr and Thr45Trp. A CD4 variant bearing these mutations bound HLA-DR1 with K(D) = 8.8 μM, compared with >400 μM for wild-type CD4. To understand the basis for improved affinity, we determined the structure of this CD4 variant in complex with HLA-DR1 to 2.4 Å resolution. The structure provides an atomic-level description of the CD4-binding site on MHC class II and reveals how CD4 recognizes highly polymorphic HLA-DR, -DP, and -DQ molecules by targeting invariant residues in their α2 and β2 domains. In addition, the CD4 mutants reported here constitute unique tools for probing the influence of CD4 affinity on T-cell activation and development.


    Organizational Affiliation

    W. M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, MD 20850, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DR alpha chain
A, D
182Homo sapiensMutation(s): 0 
Gene Names: HLA-DRA (HLA-DRA1)
Find proteins for P01903 (Homo sapiens)
Go to Gene View: HLA-DRA
Go to UniProtKB:  P01903
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
HLA class II histocompatibility antigen, DRB1-1 beta chain
B, E
193Homo sapiensMutation(s): 0 
Gene Names: HLA-DRB1
Find proteins for P04229 (Homo sapiens)
Go to Gene View: HLA-DRB1
Go to UniProtKB:  P04229
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Hemagglutinin peptide
C, F
13Influenza A virus (strain A/Aichi/2/1968 H3N2)Mutation(s): 0 
Gene Names: HA
Find proteins for P03437 (Influenza A virus (strain A/Aichi/2/1968 H3N2))
Go to UniProtKB:  P03437
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
T-cell surface glycoprotein CD4
G, H
191Homo sapiensMutation(s): 0 
Gene Names: CD4
Find proteins for P01730 (Homo sapiens)
Go to Gene View: CD4
Go to UniProtKB:  P01730
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
B, D, E
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.251 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 67.260α = 90.00
b = 137.290β = 106.64
c = 88.290γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
CNSrefinement
PHASERphasing
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2011-05-20 
  • Released Date: 2011-09-21 
  • Deposition Author(s): Li, Y.

Revision History 

  • Version 1.0: 2011-09-21
    Type: Initial release
  • Version 1.1: 2011-11-16
    Type: Database references
  • Version 1.2: 2017-11-08
    Type: Refinement description