The three-dimensional structure of a T-cell antigen receptor Valpha Vbeta heterodimer reveals a novel arrangement of the Vbeta domain
| Autor: | Claudine Piras, G. Mazza, Juan C. Fontecilla-Camps, Claude Grégoire, Bernard Malissen, Dominique Housset |
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| Rok vydání: | 1997 |
| Předmět: |
Models
Molecular Conformational change Protein Conformation Stereochemistry Receptors Antigen T-Cell alpha-beta Molecular Sequence Data chemical and pharmacologic phenomena Complementarity determining region Biology Crystallography X-Ray Ligands Protein Structure Secondary General Biochemistry Genetics and Molecular Biology Cell Line Mice Protein structure Animals Amino Acid Sequence Antigens Binding site Beta (finance) Molecular Biology Peptide sequence Binding Sites Sequence Homology Amino Acid General Immunology and Microbiology General Neuroscience T-cell receptor H-2 Antigens Hydrogen Bonding Molecular biology Dimerization Alpha chain Protein Binding T-Lymphocytes Cytotoxic Research Article |
| Zdroj: | The EMBO Journal. 16:4205-4216 |
| ISSN: | 1460-2075 |
| Popis: | The crystal structure of a mouse T-cell antigen receptor (TCR) Fv fragment complexed to the Fab fragment of a specific anti-clonotypic antibody has been determined to 2.6 A resolution. The polypeptide backbone of the TCR V alpha domain is very similar to those of other crystallographically determined V alphas, whereas the V beta structure is so far unique among TCR V beta domains in that it displays a switch of the c" strand from the inner to the outer beta-sheet. The beta chain variable region of this TCR antigen-binding site is characterized by a rather elongated third complementarity-determining region (CDR3beta) that packs tightly against the CDR3 loop of the alpha chain, without leaving any intervening hydrophobic pocket. Thus, the conformation of the CDR loops with the highest potential diversity distinguishes the structure of this TCR antigen-binding site from those for which crystallographic data are available. On the basis of all these results, we infer that a significant conformational change of the CDR3beta loop found in our TCR is required for binding to its cognate peptide-MHC ligand. |
| Databáze: | OpenAIRE |
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