5WPA

Structure of human SFPQ/PSPC1 heterodimer


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.29 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.221 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal structure of a SFPQ/PSPC1 heterodimer provides insights into preferential heterodimerization of human DBHS family proteins.

Huang, J.Casas Garcia, G.P.Perugini, M.A.Fox, A.H.Bond, C.S.Lee, M.

(2018) J Biol Chem 293: 6593-6602

  • DOI: 10.1074/jbc.RA117.001451
  • Primary Citation of Related Structures:  
    5WPA

  • PubMed Abstract: 
  • Members of the Drosophila behavior human splicing (DBHS) protein family are nuclear proteins implicated in many layers of nuclear functions, including RNA biogenesis as well as DNA repair. Definitive of the DBHS protein family, the conserved DBHS domain provides a dimerization platform that is critical for the structural integrity and function of these proteins ...

    Members of the Drosophila behavior human splicing (DBHS) protein family are nuclear proteins implicated in many layers of nuclear functions, including RNA biogenesis as well as DNA repair. Definitive of the DBHS protein family, the conserved DBHS domain provides a dimerization platform that is critical for the structural integrity and function of these proteins. The three human DBHS proteins, splicing factor proline- and glutamine-rich (SFPQ), paraspeckle component 1 (PSPC1), and non-POU domain-containing octamer-binding protein (NONO), form either homo- or heterodimers; however, the relative affinity and mechanistic details of preferential heterodimerization are yet to be deciphered. Here we report the crystal structure of a SFPQ/PSPC1 heterodimer to 2.3-Å resolution and analyzed the subtle structural differences between the SFPQ/PSPC1 heterodimer and the previously characterized SFPQ homodimer. Analytical ultracentrifugation to estimate the dimerization equilibrium of the SFPQ-containing dimers revealed that the SFPQ-containing dimers dissociate at low micromolar concentrations and that the heterodimers have higher affinities than the homodimer. Moreover, we observed that the apparent dissociation constant for the SFPQ/PSPC1 heterodimer was over 6-fold lower than that of the SFPQ/NONO heterodimer. We propose that these differences in dimerization affinity may represent a potential mechanism by which PSPC1 at a lower relative cellular abundance can outcompete NONO to heterodimerize with SFPQ.


    Organizational Affiliation

    From the Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086 and mihwa.lee@latrobe.edu.au.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Splicing factor, proline- and glutamine-richA261Homo sapiensMutation(s): 0 
Gene Names: SFPQPSF
UniProt & NIH Common Fund Data Resources
Find proteins for P23246 (Homo sapiens)
Explore P23246 
Go to UniProtKB:  P23246
PHAROS:  P23246
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Paraspeckle component 1B261Homo sapiensMutation(s): 0 
Gene Names: PSPC1PSP1
UniProt & NIH Common Fund Data Resources
Find proteins for Q8WXF1 (Homo sapiens)
Explore Q8WXF1 
Go to UniProtKB:  Q8WXF1
PHAROS:  Q8WXF1
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.29 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.221 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 89.229α = 90
b = 67.841β = 95.06
c = 92.204γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report




Entry History & Funding Information

Deposition Data

  • Deposited Date: 2017-08-04 
  • Released Date: 2018-03-21 
  • Deposition Author(s): Lee, M.

Funding OrganizationLocationGrant Number
Australian Research Council (ARC)Australia--

Revision History  (Full details and data files)

  • Version 1.0: 2018-03-21
    Type: Initial release
  • Version 1.1: 2018-03-28
    Changes: Data collection, Database references
  • Version 1.2: 2018-05-09
    Changes: Data collection, Database references
  • Version 1.3: 2020-01-01
    Changes: Author supporting evidence