1sjh: Difference between revisions
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[[Image:1sjh.gif|left|200px]]<br /> | [[Image:1sjh.gif|left|200px]]<br /><applet load="1sjh" size="350" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="1sjh" size=" | |||
caption="1sjh, resolution 2.25Å" /> | caption="1sjh, resolution 2.25Å" /> | ||
'''HLA-DR1 complexed with a 13 residue HIV capsid peptide'''<br /> | '''HLA-DR1 complexed with a 13 residue HIV capsid peptide'''<br /> | ||
==Overview== | ==Overview== | ||
T cells generally recognize peptide antigens bound to MHC proteins through | T cells generally recognize peptide antigens bound to MHC proteins through contacts with residues found within or immediately flanking the seven- to nine-residue sequence accommodated in the MHC peptide-binding groove. However, some T cells require peptide residues outside this region for activation, the structural basis for which is unknown. Here, we have investigated a HIV Gag-specific T cell clone that requires an unusually long peptide antigen for activation. The crystal structure of a minimally antigenic 16-mer bound to HLA-DR1 shows that the peptide C-terminal region bends sharply into a hairpin turn as it exits the binding site, orienting peptide residues outside the MHC-binding region in position to interact with a T cell receptor. Peptide truncation and substitution studies show that both the hairpin turn and the extreme C-terminal residues are required for T cell activation. These results demonstrate a previously unrecognized mode of MHC-peptide-T cell receptor interaction. | ||
==About this Structure== | ==About this Structure== | ||
1SJH is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http:// | 1SJH is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SJH OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
[[Category: Norris, P | [[Category: Norris, P J.]] | ||
[[Category: Stern, L | [[Category: Stern, L J.]] | ||
[[Category: Strug, I.]] | [[Category: Strug, I.]] | ||
[[Category: Walker, B | [[Category: Walker, B D.]] | ||
[[Category: Zavala-Ruiz, Z.]] | [[Category: Zavala-Ruiz, Z.]] | ||
[[Category: antigen]] | [[Category: antigen]] | ||
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[[Category: superantigen]] | [[Category: superantigen]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:02:07 2008'' | ||
Revision as of 16:02, 21 February 2008
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HLA-DR1 complexed with a 13 residue HIV capsid peptide
OverviewOverview
T cells generally recognize peptide antigens bound to MHC proteins through contacts with residues found within or immediately flanking the seven- to nine-residue sequence accommodated in the MHC peptide-binding groove. However, some T cells require peptide residues outside this region for activation, the structural basis for which is unknown. Here, we have investigated a HIV Gag-specific T cell clone that requires an unusually long peptide antigen for activation. The crystal structure of a minimally antigenic 16-mer bound to HLA-DR1 shows that the peptide C-terminal region bends sharply into a hairpin turn as it exits the binding site, orienting peptide residues outside the MHC-binding region in position to interact with a T cell receptor. Peptide truncation and substitution studies show that both the hairpin turn and the extreme C-terminal residues are required for T cell activation. These results demonstrate a previously unrecognized mode of MHC-peptide-T cell receptor interaction.
About this StructureAbout this Structure
1SJH is a Protein complex structure of sequences from Homo sapiens and Staphylococcus aureus. Full crystallographic information is available from OCA.
ReferenceReference
A hairpin turn in a class II MHC-bound peptide orients residues outside the binding groove for T cell recognition., Zavala-Ruiz Z, Strug I, Walker BD, Norris PJ, Stern LJ, Proc Natl Acad Sci U S A. 2004 Sep 7;101(36):13279-84. Epub 2004 Aug 26. PMID:15331779
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