Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 52.02 kDa 
• Atom Count: 3573 
• Modelled Residue Count: 447 
• Deposited Residue Count: 480 
• Unique protein chains: 2

1PJM

Mouse Importin alpha-bipartite NLS from human retinoblastoma protein Complex

• DOI: 10.2210/pdb1PJM/pdb

• Classification: PROTEIN TRANSPORT
• Organism(s): Mus musculus
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2003-06-03 Released: 2003-08-19 
• Deposition Author(s): Fontes, M.R.M., Teh, T., Jans, D., Brinkworth, R.I., Kobe, B.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.239 
• R-Value Work: 0.204 
• R-Value Observed: 0.204 

Literature

Structural basis for the specificity of bipartite nuclear localization sequence binding by importin-alpha

Fontes, M.R.M., Teh, T., Jans, D., Brinkworth, R.I., Kobe, B.

(2003) J Biol Chem 278: 27981-27987

• PubMed: 12695505 
• DOI: 10.1074/jbc.M303275200
• Primary Citation of Related Structures:  
  1PJN, 1PJM


• PubMed Abstract: 
  

Importin-alpha is the nuclear import receptor that recognizes cargo proteins carrying conventional basic monopartite and bipartite nuclear localization sequences (NLSs) and facilitates their transport into the nucleus. Bipartite NLSs contain two clusters of basic residues, connected by linkers of variable lengths. To determine the structural basis of the recognition of diverse bipartite NLSs by mammalian importin-alpha, we co-crystallized a non-autoinhibited mouse receptor protein with peptides corresponding to the NLSs from human retinoblastoma protein and Xenopus laevis phosphoprotein N1N2, containing diverse sequences and lengths of the linker. We show that the basic clusters interact analogously in both NLSs, but the linker sequences adopt different conformations, whereas both make specific contacts with the receptor. The available data allow us to draw general conclusions about the specificity of NLS binding by importin-alpha and facilitate an improved definition of the consensus sequence of a conventional basic/bipartite NLS (KRX10-12KRRK) that can be used to identify novel nuclear proteins.

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Related Citations: 

• Structural basis of recognition of monopartite and bipartite nuclear localization sequences by mammalian importin-alpha
  Fontes, M.R.M., Teh, T., Kobe, B.
  (2000) J Mol Biol 297: 1183

• Biophysical Characterization of Interactions Involving Impostin-alpha during Nuclear Import
  Catimel, B., Teh, T., Fontes, M.R.M., Jennings, I.G., Jans, D., Howlett, G.J., Nice, E.C., Kobe, B.
  (2001) J Biol Chem 276: 34189

• Autoinhibition by an internal nuclear localization signal reveled by the crystal structure of mammalian importin alpha
  Kobe, B.
  (1999) Nat Struct Biol 6: 388

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Organizational Affiliation: 

Structural Biology Laboratory, St. Vincent's Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065, Australia.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Retinoblastoma-associated protein	A	20	N/A	Mutation(s): 3
UniProt & NIH Common Fund Data Resources
Find proteins for P06400 (Homo sapiens) Explore P06400  Go to UniProtKB:  P06400
PHAROS:  P06400 GTEx:  ENSG00000139687

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Importin alpha-2 subunit	B	460	Mus musculus	Mutation(s): 0  Gene Names: KPNA2 OR RCH1, Kpna2, Rch1
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: 0.239 
• R-Value Work: 0.204 
• R-Value Observed: 0.204 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 79	α = 90
b = 89.179	β = 90
c = 100.992	γ = 90

Software Package:

Software Name	Purpose
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2003-06-03 
• Released Date: 2003-08-19 
Deposition Author(s): Fontes, M.R.M., Teh, T., Jans, D., Brinkworth, R.I., Kobe, B.

Revision History  

• Version 1.0: 2003-08-19
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance