1DUZ

HUMAN CLASS I HISTOCOMPATIBILITY ANTIGEN (HLA-A 0201) IN COMPLEX WITH A NONAMERIC PEPTIDE FROM HTLV-1 TAX PROTEIN

Summary for 1DUZ

• Entry DOI: 10.2210/pdb1duz/pdb
• Related: 1DUY 1HHK
• Descriptor: HLA-A*0201, BETA-2 MICROGLOBULIN, HTLV-1 OCTAMERIC TAX PEPTIDE, ... (4 entities in total)
• Functional Keywords: immunoglobulin fold, immune system
• Biological source: Homo sapiens (human); More
• Cellular location: Membrane; Single-pass type I membrane protein: P01892; Secreted: P61769
• Total number of polymer chains: 6
• Total formula weight: 89607.68

Authors

Khan, A.R.,Baker, B.M.,Ghosh, P.,Biddison, W.E.,Wiley, D.C. (deposition date: 2000-01-19, release date: 2000-02-04, Last modification date: 2024-10-16)

Primary citation

Khan, A.R.,Baker, B.M.,Ghosh, P.,Biddison, W.E.,Wiley, D.C.
The structure and stability of an HLA-A*0201/octameric tax peptide complex with an empty conserved peptide-N-terminal binding site.
J.Immunol., 164:6398-6405, 2000

PubMed Abstract: The crystal structure of the human class I MHC molecule HLA-A2 complexed with of an octameric peptide, Tax8 (LFGYPVYV), from human T cell lymphotrophic virus-1 (HTLV-1) has been determined. This structure is compared with a newly refined, higher resolution (1.8 A) structure of HLA-A2 complexed with the nonameric Tax9 peptide (LLFGYPVYV) with one more N-terminal residue. Despite the absence of a peptide residue (P1) bound in the conserved N-terminal peptide-binding pocket of the Tax8/HLA-A2 complex, the structures of the two complexes are essentially identical. Water molecules in the Tax8 complex replace the terminal amino group of the Tax9 peptide and mediate a network of hydrogen bonds among the secondary structural elements at that end of the peptide-binding groove. Thermal denaturation measurements indicate that the Tax8 complex is much less stable, DeltaTm = 16 degrees C, than the Tax9 complex, but both can sensitize target cells for lysis by some Tax-specific CTL from HTLV-1 infected individuals. The absence of a P1 peptide residue is thus not enough to prevent formation of a "closed conformation" of the peptide-binding site. TCR affinity measurements and cytotoxic T cell assays indicate that the Tax8/HLA-A2 complex does not functionally cross-react with the A6-TCR-bearing T cell clone specific for Tax9/HLA-A2 complexes.

PubMed: 10843695

Experimental method

X-RAY DIFFRACTION (1.8 Å)