1EI4

B-DNA DODECAMER CGCGAAT(TLC)CGCG WITH INCORPORATED [3.3.0]BICYCLO-ARABINO-THYMINE-5'-PHOSPHATE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.43 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural basis of cleavage by RNase H of hybrids of arabinonucleic acids and RNA.

Minasov, G.Teplova, M.Nielsen, P.Wengel, J.Egli, M.

(2000) Biochemistry 39: 3525-3532


  • PubMed Abstract: 
  • The origins of the substrate specificity of Escherichia coli RNase H1 (termed RNase H here), an enzyme that hydrolyzes the RNA strand of DNA-RNA hybrids, are not understood at present. Although the enzyme binds double-stranded RNA, no cleavage occurs ...

    The origins of the substrate specificity of Escherichia coli RNase H1 (termed RNase H here), an enzyme that hydrolyzes the RNA strand of DNA-RNA hybrids, are not understood at present. Although the enzyme binds double-stranded RNA, no cleavage occurs with such duplexes [Lima, W. F., and Crooke, S. T. (1997) Biochemistry 36, 390]. Therefore, the hybrid substrates may not adopt a canonical A-form geometry. Furthermore, RNase H is exquisitely sensitive to chemical modification of the DNA strands in hybrid duplexes. This is particularly relevant to the RNase H-dependent pathway of antisense action. Thus, only very few of the modifications currently being evaluated as antisense therapeutics are tolerated by the enzyme, among them phosphorothioate DNA (PS-DNA). Recently, hybrids of RNA and arabinonucleic acid (ANA) as well as the 2'F-ANA analogue were shown to be substrates of RNase H [Damha, M. J., et al. (1998) J. Am. Chem. Soc. 120, 12976]. Using X-ray crystallography, we demonstrate here that ANA analogues, such as 2'F-ANA [Berger, I., et al. (1998) Nucleic Acids Res. 26, 2473] and [3.3.0]bicyclo-ANA (bc-ANA), may not be able to adopt sugar puckers that are compatible with pure A- or a B-form duplex geometries, but rather prefer the intermediate O4'-endo conformation. On the basis of the observed conformations of these ANA analogues in a DNA dodecamer duplex, we have modeled a duplex of an all-C3'-endo RNA strand and an all-O4'-endo 2'F-ANA strand. This duplex exhibits a minor groove width that is intermediate between that of A-form RNA and B-form DNA, a feature that may be exploited by the enzyme in differentiating between RNA duplexes and DNA-RNA hybrids. Therefore, the combination of the established structural and functional properties of ANA analogues helps settle existing controversies concerning the discrimination of substrates by RNase H. Knowlegde of the structure of an analogue that exhibits enhanced RNA affinity while not interfering with RNase H activity may prove helpful in the design of future antisense modifications.


    Organizational Affiliation

    Department of Molecular Pharmacology and Biological Chemistry and Drug Discovery Program, Northwestern University Medical School, Chicago, IL 60611-3008, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsLengthOrganism
DNA (5'-D(*CP*GP*CP*GP*AP*AP*(TLC)P*(TLC)P*CP*GP*CP*G)-3')A,B12N/A
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SPM
Query on SPM

Download SDF File 
Download CCD File 
B
SPERMINE
C10 H26 N4
PFNFFQXMRSDOHW-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

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Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
TLC
Query on TLC
A, B
DNA LINKINGC12 H17 N2 O9 PDT
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.43 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.198 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 25.280α = 90.00
b = 40.550β = 90.00
c = 65.130γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
SCALEPACKdata scaling
CNSrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-03-27
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance