title: Crystal structure of a full-length beta-catenin.
abstract: beta-catenin plays essential roles in cell adhesion and Wnt signaling, while deregulation of beta-catenin is associated with multiple diseases including cancers. Here, we report the crystal structures of full-length zebrafish beta-catenin and a human beta-catenin fragment that contains both the armadillo repeat and the C-terminal domains. Our structures reveal that the N-terminal region of the C-terminal domain, a key component of the C-terminal transactivation domain, forms a long alpha helix that packs on the C-terminal end of the armadillo repeat domain, and thus forms part of the beta-catenin superhelical core. The existence of this helix redefines our view of interactions of beta-catenin with some of its critical partners, including ICAT and Chibby, which may form extensive interactions with this C-terminal domain alpha helix. Our crystallographic and NMR studies also suggest that the unstructured N-terminal and C-terminal tails interact with the ordered armadillo repeat domain in a dynamic and variable manner.
authors.affiliation: Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xing
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Takemaru
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Jason D
authors.initials: JD
authors.lastname: Berndt
authors.forename: Jie J
authors.initials: JJ
authors.lastname: Zheng
authors.forename: Randall T
authors.initials: RT
authors.lastname: Moon
authors.forename: Wenqing
authors.initials: W
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018360:Crystallography, X-Ray; D006801:Humans; D008024:Ligands; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish; D051176:beta Catenin / Q000737:chemistry* / Q000378:metabolism
chemical_list: D008024:Ligands; D010446:Peptide Fragments; D051176:beta Catenin