Structure of the dimerization and beta-catenin-binding region of alpha-catenin.
In adherens junctions, alpha-catenin links the cadherin-beta-catenin complex to the actin-based cytoskeleton. alpha-catenin is a homodimer in solution, but forms a 1:1 heterodimer with beta-catenin. The crystal structure of the alpha-catenin dimerization domain, residues 82-279, shows that alpha-catenin dimerizes through formation of a four-helix bundle in which two antiparallel helices are contributed by each protomer. A slightly larger fragment, comprising residues 57-264, binds to beta-catenin. A chimera consisting of the alpha-catenin-binding region of beta-catenin linked to the amino terminus of alpha-catenin 57-264 behaves as a monomer in solution, as expected, since beta-catenin binding disrupts the alpha-catenin dimer. The crystal structure of this chimera reveals the interaction between alpha- and beta-catenin, and provides a basis for understanding adherens junction assembly.
Pokutta
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Department of Structural Biology, Stanford University School of Medicine, California 94305, USA.
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D000595:Amino Acid Sequence; D001665:Binding Sites; D017124:Conserved Sequence; D003461:Crystallography; D003598:Cytoskeletal Proteins / Q000737:chemistry*; D019281:Dimerization; D007365:Intercellular Junctions / Q000737:chemistry / Q000648:ultrastructure; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators; D016596:Vinculin / Q000737:chemistry; D051178:alpha Catenin; D051176:beta Catenin
D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D016596:Vinculin