1. An Alternative Conformation of the T-Cell Receptor α Constant Region
- Author
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van Boxel, Gijs I., Holmes, Samantha, Fugger, Lars, and Jones, E. Yvonne
- Subjects
- *
PROTEIN conformation , *T-cell receptor genes , *MAJOR histocompatibility complex , *PEPTIDES , *MYELIN basic protein , *CELLULAR signal transduction , *MOLECULAR immune response , *MOLECULAR structure - Abstract
Abstract: αβ T-cell receptors (TcRs) play a central role in cellular immune response. They are members of the Ig superfamily, with extracellular regions of the α and β chains each comprising a V-type domain and a C-type domain. We have determined the ectodomain structure of an αβ TcR, which recognizes the autoantigen myelin basic protein. The 2.0-Å-resolution structure reveals canonical main-chain conformations for the Vα, Vβ, and Cβ domains, but the Cα domain exhibits a main-chain conformation remarkably different from those previously reported for TcR crystal structures. The global IgC-like fold is maintained, but a piston-like rearrangement between BC and DE β-turns results in β-strand slippage. This substantial conformational change may represent a signaling intermediate. Our structure is the first example for the Ig fold of the increasingly recognized concept of “metamorphic proteins.” [Copyright &y& Elsevier]
- Published
- 2010
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