1IAL | pdb_00001ial

IMPORTIN ALPHA, MOUSE

• PDB DOI: https://doi.org/10.2210/pdb1IAL/pdb

• Classification: NUCLEAR IMPORT RECEPTOR
• Organism(s): Mus musculus
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 1999-01-12 Released: 1999-06-15 
• Deposition Author(s): Kobe, B.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 
  0.240 (Depositor) 
• R-Value Work: 
  0.189 (Depositor) 
• R-Value Observed: 
  0.189 (Depositor) 

Starting Model: experimental

Literature

Autoinhibition by an internal nuclear localization signal revealed by the crystal structure of mammalian importin alpha.

Kobe, B.

(1999) Nat Struct Biol 6: 388-397

• PubMed: 10201409 
• DOI: https://doi.org/10.1038/7625
• Primary Citation Related Structures: 
  1IAL


• PubMed Abstract: 
  

  Importin alpha is the nuclear import receptor that recognizes classical monopartite and bipartite nuclear localization signals (NLSs). The structure of mouse importin alpha has been determined at 2.5 A resolution. The structure shows a large C-terminal domain containing armadillo repeats, and a less structured N-terminal importin beta-binding domain containing an internal NLS bound to the NLS-binding site. The structure explains the regulatory switch between the cytoplasmic, high-affinity form, and the nuclear, low-affinity form for NLS binding of the nuclear import receptor predicted by the current models of nuclear import. Importin beta conceivably converts the low- to high-affinity form by binding to a site overlapping the autoinhibitory sequence. The structure also has implications for understanding NLS recognition, and the structures of armadillo and HEAT repeats.

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Organizational Affiliation: 
• Structural Biology Laboratory, St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia. [e-mail]

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 49.33 kDa 
• Atom Count: 3,529 
• Modeled Residue Count: 438 
• Deposited Residue Count: 453 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
IMPORTIN ALPHA	A	453	Mus musculus	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P52293 (Mus musculus) Explore P52293  Go to UniProtKB:  P52293
IMPC:  MGI:103561

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free:  0.240 (Depositor) 
• R-Value Work:  0.189 (Depositor) 
• R-Value Observed: 0.189 (Depositor) 

Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 78.549	α = 90
b = 89.675	β = 90
c = 100.562	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
DENZO	data reduction
SCALEPACK	data scaling
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 1999-06-15 
Deposition Author(s): Kobe, B.

Revision History  

• Version 1.0: 1999-06-15
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2023-08-09
  Changes: Database references, Other, Refinement description
• Version 1.4: 2024-05-22
  Changes: Data collection