1duy: Difference between revisions
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==Overview== | ==Overview== | ||
The crystal structure of the human class I MHC molecule HLA-A2 complexed | 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. | ||
==Disease== | ==Disease== | ||
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[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Baker, B | [[Category: Baker, B M.]] | ||
[[Category: Biddison, W | [[Category: Biddison, W E.]] | ||
[[Category: Ghosh, P.]] | [[Category: Ghosh, P.]] | ||
[[Category: Khan, A | [[Category: Khan, A R.]] | ||
[[Category: Wiley, D | [[Category: Wiley, D C.]] | ||
[[Category: immunoglobulin fold]] | [[Category: immunoglobulin fold]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:20:43 2008'' | ||
Revision as of 13:20, 21 February 2008
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CRYSTAL STRUCTURE OF HLA-A*0201/OCTAMERIC TAX PEPTIDE COMPLEX
OverviewOverview
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.
DiseaseDisease
Known diseases associated with this structure: Abacavir hypersensitivity, susceptibility to OMIM:[142800], Ankylosing spondylitis, susceptibility to, 1 OMIM:[142800], Hypoproteinemia, hypercatabolic OMIM:[109700], Stevens-Johnson syndrome, susceptibility to OMIM:[142800]
About this StructureAbout this Structure
1DUY is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
The structure and stability of an HLA-A*0201/octameric tax peptide complex with an empty conserved peptide-N-terminal binding site., Khan AR, Baker BM, Ghosh P, Biddison WE, Wiley DC, J Immunol. 2000 Jun 15;164(12):6398-405. PMID:10843695
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