1wa5
From Proteopedia
Crystal structure of the exportin Cse1p complexed with its cargo (Kap60p) and RanGTP
Structural highlights
Function[CSE1_YEAST] Export receptor for importin alpha (SRP1). Mediates importin-alpha re-export from the nucleus to the cytoplasm after import substrates have been released into the nucleoplasm.[1] [2] [3] [4] [IMA1_YEAST] Binds specifically and directly to substrates containing either a simple or bipartite NLS motif. Promotes docking of import substrates to the nuclear envelope. Seems to act as a cytosolic receptor for both simple and bipartite NLS motifs (By similarity).[5] [6] [7] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe nuclear import and export of macromolecular cargoes through nuclear pore complexes is mediated primarily by carriers such as importin-beta. Importins carry cargoes into the nucleus, whereas exportins carry cargoes to the cytoplasm. Transport is orchestrated by nuclear RanGTP, which dissociates cargoes from importins, but conversely is required for cargo binding to exportins. Here we present the 2.0 A crystal structure of the nuclear export complex formed by exportin Cse1p complexed with its cargo (Kap60p) and RanGTP, thereby providing a structural framework for understanding nuclear protein export and the different functions of RanGTP in export and import. In the complex, Cse1p coils around both RanGTP and Kap60p, stabilizing the RanGTP-state and clamping the Kap60p importin-beta-binding domain, ensuring that only cargo-free Kap60p is exported. Mutagenesis indicated that conformational changes in exportins couple cargo binding to high affinity for RanGTP, generating a spring-loaded molecule to facilitate disassembly of the export complex following GTP hydrolysis in the cytoplasm. Structural basis for the assembly of a nuclear export complex.,Matsuura Y, Stewart M Nature. 2004 Dec 16;432(7019):872-7. PMID:15602554[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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