1DA3

THE CRYSTAL STRUCTURE OF THE TRIGONAL DECAMER C-G-A-T-C-G-6MEA-T-C-G: A B-DNA HELIX WITH 10.6 BASE-PAIRS PER TURN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The crystal structure of the trigonal decamer C-G-A-T-C-G-6meA-T-C-G: a B-DNA helix with 10.6 base-pairs per turn.

Baikalov, I.Grzeskowiak, K.Yanagi, K.Quintana, J.Dickerson, R.E.

(1993) J.Mol.Biol. 231: 768-784

  • DOI: 10.1006/jmbi.1993.1325

  • PubMed Abstract: 
  • The B-DNA decanucleotide C-G-A-T-C-G-6meA-T-C-G has been crystallized under the same conditions used earlier for C-G-A-T-C-G-A-T-C-G, but is found to adopt a new trigonal P3(2)21 packing mode instead of the expected orthorhombic P2(1)2(1)2(1) form. U ...

    The B-DNA decanucleotide C-G-A-T-C-G-6meA-T-C-G has been crystallized under the same conditions used earlier for C-G-A-T-C-G-A-T-C-G, but is found to adopt a new trigonal P3(2)21 packing mode instead of the expected orthorhombic P2(1)2(1)2(1) form. Unit cell dimensions a = b = 33.38 A, c = 98.30 A, gamma = 120 degrees, imply ten base-pairs or one complete decamer double helix per asymmetric unit. The 2282 two-sigma data to 2.0 A refine to R = 17.2% with 45 water molecules, 1.5 hexavalent hydrated magnesium complexes, and 0.5 chloride ion per asymmetric unit. Neighboring helices interlock backbone chains and major grooves, crossing at an angle of 120 degrees in a manner that yields an excellent model for a Holliday junction. Local helix parameters differ markedly in the trigonal and orthorhombic structures, with the trigonal helix exhibiting behavior closer to that expected of B-DNA in solution. The trigonal form has an average of 10.6 base-pairs per turn, in contrast to 9.7 base-pairs per turn in the orthorhombic cell. A comparison of all known B-DNA decamer and dodecamer crystal structure analyses indicates that, the greater the cell volume per base-pair (and hence the more open the crystal structure), the closer the mean helix twist approaches an expected 10.6 base-pairs per turn.


    Related Citations: 
    • The Structure of B-Helical C-G-A-T-C-G-A-T-C-G and Comparison with C-C-A-A-C-G- T-T-G-G. The Effect of Base Pair Reversals
      Grzeskowiak, K.,Yanagi, K.,Prive, G.G.,Dickerson, R.E.
      (1991) J.Biol.Chem. 266: 8861


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of California, Los Angeles 90024.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsLengthOrganism
DNA (5'-D(*CP*GP*AP*TP*CP*GP*(6MA)P*TP*CP*G)-3')A,B10N/A
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download SDF File 
Download CCD File 
B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
6MA
Query on 6MA
A, B
DNA LINKINGC11 H16 N5 O6 PA
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 33.378α = 90.00
b = 33.378β = 90.00
c = 98.302γ = 120.00
Software Package:
Software NamePurpose
NUCLSQrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1993-04-15
    Type: Initial release
  • Version 1.1: 2008-05-22
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance