478D

CRYSTAL STRUCTURE OF THE B-DNA DODECAMER 5'-D(CGCGAA(TAF)TCGCG), WHERE TAF IS 2'-DEOXY-2'-FLUORO-ARABINO-FURANOSYL THYMINE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Atomic-resolution crystal structures of B-DNA reveal specific influences of divalent metal ions on conformation and packing.

Minasov, G.Tereshko, V.Egli, M.

(1999) J.Mol.Biol. 291: 83-99

  • DOI: 10.1006/jmbi.1999.2934
  • Primary Citation of Related Structures:  476D, 477D

  • PubMed Abstract: 
  • Crystal structures of B-form DNA have provided insights into the global and local conformational properties of the double helix, the solvent environment, drug binding and DNA packing. For example, structures of the duplex with sequence CGCGAATTCGCG, ...

    Crystal structures of B-form DNA have provided insights into the global and local conformational properties of the double helix, the solvent environment, drug binding and DNA packing. For example, structures of the duplex with sequence CGCGAATTCGCG, the Dickerson-Drew dodecamer (DDD), established a unique geometry of the central A-tract and a hydration spine in the minor groove. However, our knowledge of the various interaction modes between metal ions and DNA is very limited and almost no information exists concerning the origins of the different effects on DNA conformation and packing exerted by individual metal ions. Crystallization of the DDD duplex in the presence of Mg(2+)and Ca(2+)yields different crystal forms. The structures of the new Ca(2+)-form and isomorphous structures of oligonucleotides with sequences GGCGAATTCGCG and GCGAATTCGCG were determined at a maximum resolution of 1.3 A. These and the 1.1 A structure of the DDD Mg(2+)-form have revealed the most detailed picture yet of the ionic environment of B-DNA. In the Mg(2+)and Ca(2+)-forms, duplexes in the crystal lattice are surrounded by 13 magnesium and 11 calcium ions, respectively.Mg(2+)and Ca(2+)generate different DNA crystal lattices and stabilize different end-to-end overlaps and lateral contacts between duplexes, thus using different strategies for reducing the effective repeat length of the helix to ten base-pairs. Mg(2+)crystals allow the two outermost base-pairs at either end to interact laterally via minor groove H-bonds, turning the 12-mer into an effective 10-mer. Ca(2+)crystals, in contrast, unpair the outermost base-pair at each end, converting the helix into a 10-mer that can stack along its axis. This reduction of a 12-mer into a functional 10-mer is followed no matter what the detailed nature of the 5'-end of the chain: C-G-C-G-A-ellipsis, G-G-C-G-A-ellipsis, or a truncated G-C-G-A-ellipsis Rather than merely mediating close contacts between phosphate groups, ions are at the origin of many well-known features of the DDD duplex structure. A Mg(2+)coordinates in the major groove, contributing to kinking of the duplex at one end. While Ca(2+)resides in the minor groove, coordinating to bases via its hydration shell, two magnesium ions are located at the periphery of the minor groove, bridging phosphate groups from opposite strands and contracting the groove at one border of the A-tract.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

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

Download SDF File 
Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
TAF
Query on TAF
A, B
DNA LINKINGC10 H14 F N2 O8 PDT
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.197 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 42.310α = 90.00
b = 42.310β = 90.00
c = 99.680γ = 120.00
Software Package:
Software NamePurpose
CNSrefinement
SCALEPACKdata scaling
AMoREphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-07-19
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model