Unliganded Transportin 3

Experimental Data Snapshot

  • Resolution: 2.95 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.236 
  • R-Value Observed: 0.237 

wwPDB Validation   3D Report Full Report

This is version 1.4 of the entry. See complete history


Structural Basis for Nuclear Import of Splicing Factors by Human Transportin 3.

Maertens, G.N.Cook, N.J.Wang, W.Hare, S.Gupta, S.S.Oztop, I.Lee, K.Pye, V.E.Cosnefroy, O.Snijders, A.P.Kewalramani, V.N.Fassati, A.Engelman, A.Cherepanov, P.

(2014) Proc Natl Acad Sci U S A 111: 2728

  • DOI: https://doi.org/10.1073/pnas.1320755111
  • Primary Citation of Related Structures:  
    4C0O, 4C0P, 4C0Q

  • PubMed Abstract: 

    Transportin 3 (Tnpo3, Transportin-SR2) is implicated in nuclear import of splicing factors and HIV-1 replication. Herein, we show that the majority of cellular Tnpo3 binding partners contain arginine-serine (RS) repeat domains and present crystal structures of human Tnpo3 in its free as well as GTPase Ran- and alternative splicing factor/splicing factor 2 (ASF/SF2)-bound forms. The flexible β-karyopherin fold of Tnpo3 embraces the RNA recognition motif and RS domains of the cargo. A constellation of charged residues on and around the arginine-rich helix of Tnpo3 HEAT repeat 15 engage the phosphorylated RS domain and are critical for the recognition and nuclear import of ASF/SF2. Mutations in the same region of Tnpo3 impair its interaction with the cleavage and polyadenylation specificity factor 6 (CPSF6) and its ability to support HIV-1 replication. Steric incompatibility of the RS domain and RanGTP engagement by Tnpo3 provides the mechanism for cargo release in the nucleus. Our results elucidate the structural bases for nuclear import of splicing factors and the Tnpo3-CPSF6 nexus in HIV-1 biology.

  • Organizational Affiliation

    Division of Infectious Diseases, Imperial College London, St. Mary's Campus, London W2 1PG, United Kingdom.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C, D
923Homo sapiensMutation(s): 1 
UniProt & NIH Common Fund Data Resources
Find proteins for Q9Y5L0 (Homo sapiens)
Explore Q9Y5L0 
Go to UniProtKB:  Q9Y5L0
GTEx:  ENSG00000064419 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9Y5L0
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.95 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.236 
  • R-Value Observed: 0.237 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 96.198α = 90.64
b = 104.019β = 97.88
c = 124.89γ = 104.48
Software Package:
Software NamePurpose
XDSdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-01-22
    Type: Initial release
  • Version 1.1: 2014-01-29
    Changes: Database references, Structure summary
  • Version 1.2: 2014-02-05
    Changes: Database references
  • Version 1.3: 2014-03-05
    Changes: Database references
  • Version 1.4: 2023-12-20
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description