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Crystal structure of the human class II MHC protein HLA-DR1 complexed with an influenza virus peptide

L J Stern1, J H Brown, T S Jardetzky

  • 1Department of Biochemistry and Molecular Biology, Harvard University, Cambridge Massachusetts 62138.

Nature
|March 17, 1994
PubMed

Insights

This study reveals how an influenza peptide binds to HLA-DR1, showing a unique twist and specific pocket interactions. This binding mode, with key hydrogen bonds, differs from class I histocompatibility proteins.

Area of Science:

  • Immunology
  • Structural Biology
  • Virology

Background:

  • Human Leukocyte Antigen (HLA) molecules present peptides to T cells, crucial for immune response.
  • Understanding peptide-HLA interactions is key to vaccine development and autoimmune disease research.

Purpose of the Study:

  • To elucidate the structural basis of peptide binding to HLA-DR1.
  • To characterize the conformation and interaction details of an influenza virus peptide within the HLA-DR1 binding site.

Main Methods:

  • X-ray crystallography or cryo-EM to determine the structure of the peptide-HLA-DR1 complex.
  • Computational analysis to assess peptide surface accessibility and binding pocket interactions.

Main Results:

  • The influenza peptide adopts an extended conformation with a significant twist when bound to HLA-DR1.
  • 35% of the peptide surface is solvent-accessible, available for T cell receptor interaction.
  • Specific pockets within HLA-DR1 accommodate five peptide side chains, dictating specificity.
  • Twelve hydrogen bonds between conserved HLA-DR1 residues and the peptide backbone establish a conserved binding mode.

Conclusions:

  • The binding of influenza peptides to HLA-DR1 involves a unique, twisted conformation and specific side-chain interactions.
  • This binding mechanism is distinct from that observed in class I histocompatibility proteins, highlighting diverse peptide presentation strategies.

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