4b8p | pdb_00004b8p

rImp_alpha_A89NLS

spinqualitylabelsall models 4b8p, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4b8p is a 4 chain structure with sequence from Oryza sativa japonica group and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 4b8j, 4b8o, 2ynr, 2yns, 4ba3 Resources: FirstGlance, OCA, RCSB, PDBsum Function [IMA1A_ORYSJ] Functions in nuclear protein import. Binds specifically and directly to substrates containing either a simple or bipartite NLS motif. Promotes docking of import substrates to the nuclear envelope. Publication Abstract from PubMed In the classical nucleocytoplasmic import pathway, nuclear localization signals (NLSs) in cargo proteins are recognized by the import receptor importin-alpha. Importin-alpha has two separate NLS binding sites (the major and the minor site), both of which recognize positively charged amino acid clusters in NLSs. Little is known about the molecular basis of the unique features of the classical nuclear import pathway in plants. We determined the crystal structure of rice (Oryza sativa) importin-alpha1a at 2-A resolution. The structure reveals that the autoinhibitory mechanism mediated by the importin-beta binding domain of importin-alpha operates in plants, with NLS-mimicking sequences binding to both minor and major NLS binding sites. Consistent with yeast and mammalian proteins, rice importin-alpha binds the prototypical NLS from simian virus 40 large T-antigen preferentially at the major NLS binding site. We show that two NLSs, previously described as plant specific, bind to and are functional with plant, mammalian, and yeast importin-alpha proteins but interact with rice importin-alpha more strongly. The crystal structures of their complexes with rice importin-alpha show that they bind to the minor NLS binding site. By contrast, the crystal structures of their complexes with mouse (Mus musculus) importin-alpha show preferential binding to the major NLS binding site. Our results reveal the molecular basis of a number of features of the classical nuclear transport pathway specific to plants. Crystal Structure of Rice Importin-alpha and Structural Basis of Its Interaction with Plant-Specific Nuclear Localization Signals.,Chang CW, Counago RL, Williams SJ, Boden M, Kobe B Plant Cell. 2012 Dec 18. PMID:23250448 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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