4E6B image
Deposition Date 2012-03-15
Release Date 2012-07-11
Last Version Date 2024-02-28
Entry Detail
PDB ID:
4E6B
Keywords:
Title:
Crystal Structure of statistically disordered 19mer duplex p(CGG)3C(CUG)3
Biological Source:
Source Organism:
(Taxon ID: ) (Taxon ID: )
Method Details:
Experimental Method:
Resolution:
1.47 Å
R-Value Free:
0.21
R-Value Work:
0.20
R-Value Observed:
0.20
Space Group:
H 3
Macromolecular Entities
Polymer Type:polyribonucleotide
Molecule:5'-R(P*CP*GP*GP*CP*GP*GP*CP*GP*GP*CP*CP*UP*GP*CP*UP*GP*CP*UP*G)-3'
Chain IDs:A, B
Chain Length:4
Number of Molecules:2
Biological Source:
Polymer Type:polyribonucleotide
Molecule:5'-R(P*CP*GP*GP*CP*GP*GP*CP*GP*GP*CP*CP*UP*GP*CP*UP*GP*CP*UP*G)-3'
Chain IDs:C (auth: F), D (auth: E)
Chain Length:4
Number of Molecules:2
Biological Source:
Primary Citation
Structural dynamics of double-helical RNAs composed of CUG/CUG- and CUG/CGG-repeats.
J.Biomol.Struct.Dyn. 30 505 523 (2012)
PMID: 22731704 DOI: 10.1080/07391102.2012.687517

Abstact

Human genetic trinucleotide repeat expansion diseases (TREDs) are characterized by triplet repeat expansions, most frequently found as CNG-tracts in genome. At RNA level, such expansions suggestively result in formation of double-helical hairpins that become a potential source for small RNAs involved in RNA interference (RNAi). Here, we present three crystal structures of RNA fragments composed of triplet repeats CUG and CGG/CUG, as well as two crystal structures of same triplets in a protein-bound state. We show that both 20mer pG(CUG)(6)C and 19mer pGG(CGG)(3)(CUG)(2)CC form A-RNA duplexes, in which U·U or G·U mismatches are flanked/stabilized by two consecutive Watson-Crick G·C base pairs resulting in high-stacking GpC steps in every third position of the duplex. Despite interruption of this regularity in another 19mer, p(CGG)(3)C(CUG)(3), the oligonucleotide still forms regular double-helical structure, characterized, however, by 12 bp (rather than 11 bp) per turn. Analysis of newly determined molecular structures reveals the dynamic aspects of U·U and G·U mismatching within CNG-repetitive A-RNA and in a protein-bound state, as well as identifies an additional mode of U·U pairing essential for its dynamics and sheds the light on possible role of regularity of trinucleotide repeats for double-helical RNA structure. Findings are important for understanding the structural behavior of CNG-repetitive RNA double helices implicated in TREDs.

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Primary Citation of related structures