Abstract
The SH3 domain, which normally recognizes proline-rich sequences, has the potential to bind motifs with an RxxK consensus. To explore this novel specificity, we have determined the solution structure of the Gads T cell adaptor C-terminal SH3 domain in complex with an RSTK-containing peptide, representing its physiological binding site on the SLP-76 docking protein. The SLP-76 peptide engages four distinct binding pockets on the surface of the Gads SH3 domain and upon binding adopts a unique structure characterized by a right-handed 3(10) helix at the RSTK locus, in contrast to the left-handed polyproline type II helix formed by canonical proline-rich SH3 ligands. The structure, and supporting mutagenesis and peptide binding data, reveal a novel mode of ligand recognition by SH3 domains.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing*
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Amino Acid Motifs / genetics
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Amino Acid Sequence
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Binding Sites
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Carrier Proteins / chemistry*
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Carrier Proteins / genetics
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Carrier Proteins / metabolism*
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Humans
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In Vitro Techniques
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Jurkat Cells
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Ligands
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Macromolecular Substances
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Models, Molecular
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Mutagenesis, Site-Directed
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Phosphoproteins / chemistry*
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Phosphoproteins / genetics
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Phosphoproteins / metabolism*
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Proline / chemistry
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Static Electricity
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src Homology Domains / genetics
Substances
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Adaptor Proteins, Signal Transducing
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Carrier Proteins
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GRAP2 protein, human
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Ligands
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Macromolecular Substances
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Phosphoproteins
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Recombinant Proteins
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SLP-76 signal Transducing adaptor proteins
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Proline