Structure of a WW domain containing fragment of dystrophin in complex with beta-dystroglycan.
Dystrophin and beta-dystroglycan are components of the dystrophin-glycoprotein complex (DGC), a multimolecular assembly that spans the cell membrane and links the actin cytoskeleton to the extracellular basal lamina. Defects in the dystrophin gene are the cause of Duchenne and Becker muscular dystrophies. The C-terminal region of dystrophin binds the cytoplasmic tail of beta-dystroglycan, in part through the interaction of its WW domain with a proline-rich motif in the tail of beta-dystroglycan. Here we report the crystal structure of this portion of dystrophin in complex with the proline-rich binding site in beta-dystroglycan. The structure shows that the dystrophin WW domain is embedded in an adjacent helical region that contains two EF-hand-like domains. The beta-dystroglycan peptide binds a composite surface formed by the WW domain and one of these EF-hands. Additionally, the structure reveals striking similarities in the mechanisms of proline recognition employed by WW domains and SH3 domains.
Department of Cancer Biology, Dana Farber Cancer Institute, 44 Binney Street, Boston, Massachusetts 02115, USA.
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Huang
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Poy
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Zhang
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Joachimiak
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Sudol
M J
MJ
Eck
D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000378:metabolism*; D049030:Dystroglycans; D016189:Dystrophin / Q000737:chemistry* / Q000378:metabolism*; D020832:EF Hand Motifs; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D011485:Protein Binding; D016415:Sequence Alignment; D013379:Substrate Specificity; D014364:Tryptophan / Q000378:metabolism*; D018909:src Homology Domains
D003598:Cytoskeletal Proteins; C483081:DAG1 protein, human; D016189:Dystrophin; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D049030:Dystroglycans; D014364:Tryptophan; D011392:Proline