Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

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

Macromolecule Content

• Total Structure Weight: 13419.94 
• Atom Count: 856 
• Residue Count: 112 
• Unique protein chains: 1

4DNN

Crystal structure of the Quaking Qua1 homodimerization domain

• DOI: 10.2210/pdb4DNN/pdb

• Classification: SPLICING
• Organism(s): Mus musculus
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): 1 


• Deposited: 2012-02-08 Released: 2012-09-12 
• Deposition Author(s): Beuck, C., Qu, S., Williamson, J.R.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.1 Å
• R-Value Free: 0.252 
• R-Value Work: 0.216 

Literature

Structural Analysis of the Quaking Homodimerization Interface.

Beuck, C., Qu, S., Fagg, W.S., Ares, M., Williamson, J.R.

(2012) J.Mol.Biol. 423: 766-781

• PubMed: 22982292 
• DOI: 10.1016/j.jmb.2012.08.027


• PubMed Abstract: 
  

Quaking (QkI) is a prototypical member of the STAR (signal transducer and activator of RNA) protein family, which plays key roles in posttranscriptional gene regulation by controlling mRNA translation, stability and splicing. QkI-5 has been shown to regulate mRNA expression in the central nervous system, but little is known about its roles in other tissues. STAR proteins function as dimers and bind to bipartite RNA sequences; however, the structural and functional roles of homodimerization and heterodimerization are still unclear. Here, we present the crystal structure of the QkI dimerization domain, which adopts a similar stacked helix-turn-helix arrangement as its homologs GLD-1 (germ line development defective-1) and Sam68 (Src-associated protein during mitosis, 68kDa) but differs by an additional helix inserted in the dimer interface. Variability of the dimer interface residues likely ensures selective homodimerization by preventing association with non-cognate STAR family proteins in the cell. Mutations that inhibit dimerization also significantly impair RNA binding in vitro, alter QkI-5 protein levels and impair QkI function in a splicing assay in vivo. Together, our results indicate that a functional Qua1 homodimerization domain is required for QkI-5 function in mammalian cells.

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Organizational Affiliation: 

Department of Molecular Biology, Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Protein quaking	A, B	56	Mus musculus	Mutation(s): 1  Gene Names: Qki (Qk, Qk1, Qka1)
Find proteins for Q9QYS9 (Mus musculus) Go to UniProtKB:  Q9QYS9

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
CA	B	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A, B	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.1 Å
• R-Value Free: 0.252 
• R-Value Work: 0.216 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length (Å)	Angle (°)
a = 33.983	α = 90.00
b = 36.024	β = 90.00
c = 92.814	γ = 90.00

Software Package:

Software Name	Purpose
HKL-2000	data scaling
HKL-2000	data reduction
PHENIX	model building
PHENIX	refinement
PHENIX	phasing
Blu-Ice	data collection

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2012-02-08 
• Released Date: 2012-09-12 
• Deposition Author(s): Beuck, C., Qu, S., Williamson, J.R.

Revision History 

• Version 1.0: 2012-09-12
  Type: Initial release
• Version 1.1: 2012-10-17
  Type: Database references