411D

DUPLEX [5'-D(GCGTA+TACGC)]2 WITH INCORPORATED 2'-O-METHOXYETHYL RIBONUCLEOSIDE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.168 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Correlating structure and stability of DNA duplexes with incorporated 2'-O-modified RNA analogues.

Tereshko, V.Portmann, S.Tay, E.C.Martin, P.Natt, F.Altmann, K.H.Egli, M.

(1998) Biochemistry 37: 10626-10634

  • DOI: 10.1021/bi980392a
  • Primary Citation of Related Structures:  410D, 412D

  • PubMed Abstract: 
  • Chemically modified nucleic acids are currently being evaluated as potential antisense compounds for therapeutic applications. 2'-O-Ethylene glycol substituted oligoribonucleotides are second-generation antisense inhibitors of gene expression with pr ...

    Chemically modified nucleic acids are currently being evaluated as potential antisense compounds for therapeutic applications. 2'-O-Ethylene glycol substituted oligoribonucleotides are second-generation antisense inhibitors of gene expression with promising features for in vivo use. Relative to DNA, they display improved RNA affinity and higher nuclease resistance. Moreover, chimeric oligonucleotides with 2'-O-methoxyethyl ribonucleoside wings and a central DNA phosphorothioate window have been shown to effectively reduce the growth of tumors in animal models at low doses. Using X-ray crystallography, we have determined the structures of three A-form DNA duplexes containing the following 2'-O-modified ribothymidine building blocks: 2'-O-methoxyethyl ribo-T, 2'-O-methyl[tri(oxyethyl)] ribo-T, and 2'-O-ethoxymethylene ribo-T. In contrast to 2'-O-ethylene glycol substituents, the presence of a 2'-O-ethoxymethylene group leads to slightly reduced RNA affinity of the corresponding oligonucleotides. The three structures allow a qualitative rationalization of the differing stabilities of duplexes between oligonucleotides comprising these types of 2'-O-modified ribonucleotides and complementary RNAs. The stabilizing 2'-O-ethylene glycol substituents are conformationally preorganized for the duplex state. Thus, the presence of one or several ethylene glycol moieties may reduce the conformational space of the substituents in an oligonucleotide single strand. In addition, most of these preferred conformations appear to be compatible with the minor groove topology in an A-type duplex. Factors that contribute to the conformational rigidity of the 2'-O-substituents are anomeric and gauche effects, electrostatic interactions between backbone and substituent, and bound water molecules.


    Organizational Affiliation

    Drug Discovery Program, Northwestern University Medical School, Chicago, Illinois 60611-3008, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsLengthOrganism
DNA (5'-D(*GP*CP*GP*TP*AP*(T39)P*AP*CP*GP*C)-3')A,B10N/A
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
T39
Query on T39
A, B
RNA LINKINGC13 H21 N2 O10 PDT
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.168 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 24.930α = 90.00
b = 44.590β = 90.00
c = 45.380γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
X-PLORrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-07-17
    Type: Initial release
  • Version 1.1: 2008-05-22
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2013-01-16
    Type: Atomic model