4PCJ | pdb_00004pcj

Modifications to toxic CUG RNAs induce structural stability and rescue mis-splicing in Myotonic Dystrophy


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 
    0.268 (Depositor), 0.269 (DCC) 
  • R-Value Work: 
    0.196 (Depositor), 0.203 (DCC) 
  • R-Value Observed: 
    0.200 (Depositor) 

Starting Model: experimental
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This is version 1.4 of the entry. See complete history

Literature

Modifications to toxic CUG RNAs induce structural stability, rescue mis-splicing in a myotonic dystrophy cell model and reduce toxicity in a myotonic dystrophy zebrafish model.

deLorimier, E.Coonrod, L.A.Copperman, J.Taber, A.Reister, E.E.Sharma, K.Todd, P.K.Guenza, M.G.Berglund, J.A.

(2014) Nucleic Acids Res 42: 12768-12778

  • DOI: https://doi.org/10.1093/nar/gku941
  • Primary Citation Related Structures: 
    4PCJ

  • PubMed Abstract: 

    CUG repeat expansions in the 3' UTR of dystrophia myotonica protein kinase (DMPK) cause myotonic dystrophy type 1 (DM1). As RNA, these repeats elicit toxicity by sequestering splicing proteins, such as MBNL1, into protein-RNA aggregates. Structural studies demonstrate that CUG repeats can form A-form helices, suggesting that repeat secondary structure could be important in pathogenicity. To evaluate this hypothesis, we utilized structure-stabilizing RNA modifications pseudouridine (Ψ) and 2'-O-methylation to determine if stabilization of CUG helical conformations affected toxicity. CUG repeats modified with Ψ or 2'-O-methyl groups exhibited enhanced structural stability and reduced affinity for MBNL1. Molecular dynamics and X-ray crystallography suggest a potential water-bridging mechanism for Ψ-mediated CUG repeat stabilization. Ψ modification of CUG repeats rescued mis-splicing in a DM1 cell model and prevented CUG repeat toxicity in zebrafish embryos. This study indicates that the structure of toxic RNAs has a significant role in controlling the onset of neuromuscular diseases.


  • Organizational Affiliation
    • Department of Chemistry and Biochemistry, Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA.

Macromolecule Content 

  • Total Structure Weight: 11.38 kDa 
  • Atom Count: 814 
  • Modeled Residue Count: 35 
  • Deposited Residue Count: 35 
  • Unique nucleic acid chains: 1

Macromolecules

Find similar nucleic acids by:  (by identity cutoff) 
Entity ID: 1
MoleculeChains LengthOrganismImage
trCUG-3('5)35synthetic construct
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free:  0.268 (Depositor), 0.269 (DCC) 
  • R-Value Work:  0.196 (Depositor), 0.203 (DCC) 
  • R-Value Observed: 0.200 (Depositor) 
Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.705α = 90
b = 69.705β = 90
c = 67.797γ = 120
Software Package:
Software NamePurpose
REFMACrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-10-29
    Type: Initial release
  • Version 1.1: 2014-11-26
    Changes: Database references
  • Version 1.2: 2014-12-17
    Changes: Database references
  • Version 1.3: 2017-09-06
    Changes: Author supporting evidence, Database references, Derived calculations, Other, Source and taxonomy, Structure summary
  • Version 1.4: 2023-09-27
    Changes: Data collection, Database references, Derived calculations, Refinement description