1WV5

X-ray structure of the A-decamer GCGTATACGC with a single 2'-o-butyl thymine in place of T6, Mg-form

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.237 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history. 

Literature

Probing the influence of stereoelectronic effects on the biophysical properties of oligonucleotides: comprehensive analysis of the RNA affinity, nuclease resistance, and crystal structure of ten 2'-O-ribonucleic acid modifications.

Egli, M., Minasov, G., Tereshko, V., Pallan, P.S., Teplova, M., Inamati, G.B., Lesnik, E.A., Owens, S.R., Ross, B.S., Prakash, T.P., Manoharan, M.

(2005) Biochemistry 44: 9045-9057

  • DOI: 10.1021/bi050574m
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • The syntheses of 10 new RNA 2'-O-modifications, their incorporation into oligonucleotides, and an evaluation of their properties such as RNA affinity and nuclease resistance relevant to antisense activity are presented. All modifications combined wit ...

    The syntheses of 10 new RNA 2'-O-modifications, their incorporation into oligonucleotides, and an evaluation of their properties such as RNA affinity and nuclease resistance relevant to antisense activity are presented. All modifications combined with the natural phosphate backbone lead to significant gains in terms of the stability of hybridization to RNA relative to the first-generation DNA phosphorothioates (PS-DNA). The nuclease resistance afforded in particular by the 2'-O-modifications carrying a positive charge surpasses that of PS-DNA. However, small electronegative 2'-O-substituents, while enhancing the RNA affinity, do not sufficiently protect against degradation by nucleases. Similarly, oligonucleotides containing 3'-terminal residues modified with the relatively large 2'-O-[2-(benzyloxy)ethyl] substituent are rapidly degraded by exonucleases, proving wrong the assumption that steric bulk will generally improve protection against nuclease digestion. To analyze the factors that contribute to the enhanced RNA affinity and nuclease resistance we determined crystal structures of self-complementary A-form DNA decamer duplexes containing single 2'-O-modified thymidines per strand. Conformational preorganization of substituents, favorable electrostatic interactions between substituent and sugar-phosphate backbone, and a stable water structure in the vicinity of the 2'-O-modification all appear to contribute to the improved RNA affinity. Close association of positively charged substituents and phosphate groups was observed in the structures with modifications that protect most effectively against nucleases. The promising properties exhibited by some of the analyzed 2'-O-modifications may warrant a more detailed evaluation of their potential for in vivo antisense applications. Chemical modification of RNA can also be expected to significantly improve the efficacy of small interfering RNAs (siRNA). Therefore, the 2'-O-modifications introduced here may benefit the development of RNAi therapeutics.

    Organizational Affiliation: 

    Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, USA. martin.egli@vanderbilt.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsLengthOrganism
5'-D(*GP*CP*GP*TP*AP*(2BT)P*AP*CP*GP*C)-3'A,B10N/A
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG
Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
2BT
Query on 2BT
A, B
RNA LINKINGC14 H23 N2 O9 PDT
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.237 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 44.435α = 90.00
b = 44.434β = 90.00
c = 69.533γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
AMoREphasing
HKL-2000data reduction

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-06-28
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance