2C1M

Nup50:importin-alpha complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.221 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Nup50/Npap60 Function in Nuclear Protein Import Complex Disassembly and Importin Recycling.

Matsuura, Y.Stewart, M.

(2005) Embo J. 24: 3681

  • DOI: 10.1038/sj.emboj.7600843
  • Primary Citation of Related Structures:  2C1T

  • PubMed Abstract: 
  • Nuclear import of proteins containing classical nuclear localization signals (NLS) is mediated by the importin-alpha:beta complex that binds cargo in the cytoplasm and facilitates its passage through nuclear pores, after which nuclear RanGTP dissocia ...

    Nuclear import of proteins containing classical nuclear localization signals (NLS) is mediated by the importin-alpha:beta complex that binds cargo in the cytoplasm and facilitates its passage through nuclear pores, after which nuclear RanGTP dissociates the import complex and the importins are recycled. In vertebrates, import is stimulated by nucleoporin Nup50, which has been proposed to accompany the import complex through nuclear pores. However, we show here that the Nup50 N-terminal domain actively displaces NLSs from importin-alpha, which would be more consistent with Nup50 functioning to coordinate import complex disassembly and importin recycling. The crystal structure of the importin-alpha:Nup50 complex shows that Nup50 binds at two sites on importin-alpha. One site overlaps the secondary NLS-binding site, whereas the second extends along the importin-alpha C-terminus. Mutagenesis indicates that interaction at both sites is required for Nup50 to displace NLSs. The Cse1p:Kap60p:RanGTP complex structure suggests how Nup50 is then displaced on formation of the importin-alpha export complex. These results provide a rationale for understanding the series of interactions that orchestrate the terminal steps of nuclear protein import.


    Organizational Affiliation

    MRC Laboratory of Molecular Biology, Cambridge, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
IMPORTIN-ALPHA2 SUBUNIT
A
424Mus musculusGene Names: Kpna2 (Rch1)
Find proteins for P52293 (Mus musculus)
Go to UniProtKB:  P52293
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
NUCLEOPORIN 50 KDA
B
46Mus musculusGene Names: Nup50 (Npap60)
Find proteins for Q9JIH2 (Mus musculus)
Go to UniProtKB:  Q9JIH2
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.221 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 74.467α = 90.00
b = 74.467β = 90.00
c = 188.023γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
MOSFLMdata reduction
SCALAdata scaling
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-11-23
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance