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1fng
From Proteopedia
(New page: 200px<br /><applet load="1fng" size="450" color="white" frame="true" align="right" spinBox="true" caption="1fng, resolution 1.90Å" /> '''HISTOCOMPATIBILITY A...) |
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| - | [[Image:1fng.gif|left|200px]]<br /><applet load="1fng" size=" | + | [[Image:1fng.gif|left|200px]]<br /><applet load="1fng" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1fng, resolution 1.90Å" /> | caption="1fng, resolution 1.90Å" /> | ||
'''HISTOCOMPATIBILITY ANTIGEN'''<br /> | '''HISTOCOMPATIBILITY ANTIGEN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | To better understand TCR discrimination of multiple ligands, we have | + | To better understand TCR discrimination of multiple ligands, we have analyzed the crystal structures of two Hb peptide/I-E(k) complexes that differ by only a single amino acid substitution at the P6 anchor position within the peptide (E73D). Detailed comparison of multiple independently determined structures at 1.9 A resolution reveals that removal of a single buried methylene group can alter a critical portion of the TCR recognition surface. Significant variance was observed in the peptide P5-P8 main chain as well as a rotamer difference at LeuP8, approximately 10 A distal from the substitution. No significant variations were observed in the conformation of the two MHC class II molecules. The ligand alteration results in two peptide/MHC complexes that generate bulk T cell responses that are distinct and essentially nonoverlapping. For the Hb-specific T cell 3.L2, substitution reduces the potency of the ligand 1000-fold. Soluble 3.L2 TCR binds the two peptide/MHC complexes with similar affinity, although with faster kinetics. These results highlight the role of subtle variations in MHC Ag presentation on T cell activation and signaling. |
==About this Structure== | ==About this Structure== | ||
| - | 1FNG is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with NAG as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1FNG is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=NAG:'>NAG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FNG OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Fremont, D | + | [[Category: Fremont, D H.]] |
| - | [[Category: Miley, M | + | [[Category: Miley, M J.]] |
| - | [[Category: Nelson, C | + | [[Category: Nelson, C A.]] |
[[Category: NAG]] | [[Category: NAG]] | ||
[[Category: histocompatibility antigen]] | [[Category: histocompatibility antigen]] | ||
| Line 22: | Line 22: | ||
[[Category: peptide]] | [[Category: peptide]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:40:31 2008'' |
Revision as of 10:40, 21 February 2008
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HISTOCOMPATIBILITY ANTIGEN
Overview
To better understand TCR discrimination of multiple ligands, we have analyzed the crystal structures of two Hb peptide/I-E(k) complexes that differ by only a single amino acid substitution at the P6 anchor position within the peptide (E73D). Detailed comparison of multiple independently determined structures at 1.9 A resolution reveals that removal of a single buried methylene group can alter a critical portion of the TCR recognition surface. Significant variance was observed in the peptide P5-P8 main chain as well as a rotamer difference at LeuP8, approximately 10 A distal from the substitution. No significant variations were observed in the conformation of the two MHC class II molecules. The ligand alteration results in two peptide/MHC complexes that generate bulk T cell responses that are distinct and essentially nonoverlapping. For the Hb-specific T cell 3.L2, substitution reduces the potency of the ligand 1000-fold. Soluble 3.L2 TCR binds the two peptide/MHC complexes with similar affinity, although with faster kinetics. These results highlight the role of subtle variations in MHC Ag presentation on T cell activation and signaling.
About this Structure
1FNG is a Protein complex structure of sequences from Mus musculus with as ligand. Full crystallographic information is available from OCA.
Reference
Structural and functional consequences of altering a peptide MHC anchor residue., Kersh GJ, Miley MJ, Nelson CA, Grakoui A, Horvath S, Donermeyer DL, Kappler J, Allen PM, Fremont DH, J Immunol. 2001 Mar 1;166(5):3345-54. PMID:11207290
Page seeded by OCA on Thu Feb 21 12:40:31 2008
