Crystal structure of the V alpha domain of a T cell antigen receptor.

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TitleCrystal structure of the V alpha domain of a T cell antigen receptor.
Publication TypeJournal Article
Year of Publication1995
AuthorsFields, BA, Ober, B, Malchiodi, EL, Lebedeva, MI, Braden, BC, Ysern, X, Kim, JK, Shao, X, Ward, ES, Mariuzza, RA
JournalScience
Volume270
Issue5243
Pagination1821-4
Date Published1995 Dec 15
ISSN0036-8075
KeywordsAnimals, Crystallography, X-Ray, Humans, Mice, Models, Molecular, Protein Conformation, Protein Folding, Receptors, Antigen, T-Cell, alpha-beta
Abstract

The crystal structure of the V alpha domain of a T cell antigen receptor (TCR) was determined at a resolution of 2.2 angstroms. This structure represents an immunoglobulin topology set different from those previously described. A switch in a polypeptide strand from one beta sheet to the other enables a pair of V alpha homodimers to pack together to form a tetramer, such that the homodimers are parallel to each other and all hypervariable loops face in one direction. On the basis of the observed mode of V alpha association, a model of an (alpha beta)2 TCR tetramer can be positioned relative to the major histocompatibility complex class II (alpha beta)2 tetramer with the third hypervariable loop of V alpha over the amino-terminal portion of the antigenic peptide and the corresponding loop of V beta over its carboxyl-terminal residues. TCR dimerization that is mediated by the alpha chain may contribute to the coupling of antigen recognition to signal transduction during T cell activation.

Alternate JournalScience
PubMed ID8525376
Grant ListAI31592 / AI / NIAID NIH HHS / United States
GM52801 / GM / NIGMS NIH HHS / United States