2G92

Crystal Structure Analysis of the RNA Dodecamer CGC-(NF2)-AAUUAGCG, with an Incorporated 2,4-Difluorotoluyl Residue (NF2)

  • Classification: RNA
  • Mutation(s): No 

  • Deposited: 2006-03-04 Released: 2006-04-18 
  • Deposition Author(s): Egli, M., Li, F.

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.61 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.199 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history. 


Literature

Gene silencing activity of siRNAs with a ribo-difluorotoluyl nucleotide.

Xia, J., Noronha, A., Toudjarska, I., Li, F., Akinc, A., Braich, R., Frank-Kamenetsky, M., Rajeev, K.G., Egli, M., Manoharan, M.

(2006) ACS Chem Biol 1: 176-183

  • DOI: 10.1021/cb600063p
  • Primary Citation of Related Structures:  
    2G92

  • PubMed Abstract: 

    • Recently, chemically synthesized short interfering RNA (siRNA) duplexes have been used with success for gene silencing. Chemical modification is desired for therapeutic applications to improve biostability and pharmacokinetic properties; chemical modification may also provide insight into the mechanism of silencing ...

    Recently, chemically synthesized short interfering RNA (siRNA) duplexes have been used with success for gene silencing. Chemical modification is desired for therapeutic applications to improve biostability and pharmacokinetic properties; chemical modification may also provide insight into the mechanism of silencing. siRNA duplexes containing the 2,4-difluorotoluyl ribonucleoside (rF) were synthesized to evaluate the effect of noncanonical nucleoside mimetics on RNA interference. 5'-Modification of the guide strand with rF did not alter silencing relative to unmodified control. Internal uridine to rF substitutions were well-tolerated. Thermal melting analysis showed that the base pair between rF and adenosine (A) was destabilizing relative to a uridine-adenosine pair, although it was slightly less destabilizing than other mismatches. The crystal structure of a duplex containing rFoA pairs showed local structural variations relative to a canonical RNA helix. As the fluorine atoms cannot act as hydrogen bond acceptors and are more hydrophobic than uridine, there was an absence of a well-ordered water structure around the rF residues in both grooves. siRNAs with the rF modification effectively silenced gene expression and offered improved nuclease resistance in serum; therefore, evaluation of this modification in therapeutic siRNAs is warranted.

    Organizational Affiliation: 

    Alnylam Pharmaceuticals, Inc., 300 Third Street, Cambridge, Massachusetts 02142, USA.



Macromolecules

Find similar nucleic acids by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChainsLengthOrganismImage
5'-R(*CP*GP*CP*(NF2)P*AP*AP*UP*UP*AP*GP*CP*G)-3'A, B 12N/A
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.61 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.196 
  • R-Value Observed: 0.199 
  • Space Group: P 31
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 28.614α = 90
b = 28.614β = 90
c = 63.171γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
X-GENdata reduction
X-GENdata scaling
EPMRphasing

Structure Validation

View Full Validation Report



View more in-depth experimental data

Entry History 

Deposition Data

  • Deposited Date: 2006-03-04 
  • Released Date: 2006-04-18 
    • Deposition Author(s): Egli, M., Li, F.

Revision History  (Full details and data files)

  • Version 1.0: 2006-04-18
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-18
    Changes: Refinement description