1D98 | pdb_00001d98

THE STRUCTURE OF AN OLIGO(DA).OLIGO(DT) TRACT AND ITS BIOLOGICAL IMPLICATIONS

• PDB DOI: https://doi.org/10.2210/pdb1D98/pdb
• NAKB: 1D98

• Classification: DNA
• Mutation(s): No 


• Deposited: 1992-10-17 Released: 1993-04-15 
• Deposition Author(s): Nelson, H.C.M., Finch, J.T., Luisi, B.F., Klug, A.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Observed: 
  0.200 (Depositor) 

Literature

The structure of an oligo(dA).oligo(dT) tract and its biological implications.

Nelson, H.C., Finch, J.T., Luisi, B.F., Klug, A.

(1987) Nature 330: 221-226

• PubMed: 3670410 
• DOI: https://doi.org/10.1038/330221a0
• Primary Citation Related Structures: 
  1D98


• PubMed Abstract: 
  

  Poly(dA).poly(dT) has unusual properties in that it cannot associate into nucleosomes and short, phased runs of it cause DNA bending. The crystal structure of a B-type DNA dodecamer containing a homopolymeric run of six A.T base pairs shows that this region possesses special structural features, including a system of bifurcated hydrogen bonds, which explains some of the properties of this simple homopolymer.

---

Organizational Affiliation: 
• Medical Research Council Laboratory of Molecular Biology, Cambridge, UK.

Biological Assembly 1  

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content 

• Total Structure Weight: 7.32 kDa 
• Atom Count: 513 
• Modeled Residue Count: 24 
• Deposited Residue Count: 24 
• Unique nucleic acid chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Length	Organism	Image
DNA (5'-D(*CP*GP*CP*AP*AP*AP*AP*AP*AP*GP*CP*G)-3')	A	12	N/A

Entity ID: 2
Molecule	Chains	Length	Organism	Image
DNA (5'-D(*CP*GP*CP*TP*TP*TP*TP*TP*TP*GP*CP*G)-3')	B	12	N/A

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Observed: 0.200 (Depositor) 

Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 25.4	α = 90
b = 40.7	β = 90
c = 65.8	γ = 90

Software Package:

Software Name	Purpose
NUCLSQ	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 1993-04-15 
Deposition Author(s): Nelson, H.C.M., Finch, J.T., Luisi, B.F., Klug, A.

Revision History  

• Version 1.0: 1993-04-15
  Type: Initial release
  
• Version 1.1: 2008-05-22
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-02-07
  Changes: Data collection, Database references