1DL8

CRYSTAL STRUCTURE OF 5-F-9-AMINO-(N-(2-DIMETHYLAMINO)ETHYL)ACRIDINE-4-CARBOXAMIDE BOUND TO D(CGTACG)2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.214 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Acridinecarboxamide topoisomerase poisons: structural and kinetic studies of the DNA complexes of 5-substituted 9-amino-(N-(2-dimethylamino)ethyl)acridine-4-carboxamides.

Adams, A.Guss, J.M.Collyer, C.A.Denny, W.A.Prakash, A.S.Wakelin, L.P.

(2000) Mol.Pharmacol. 58: 649-658


  • PubMed Abstract: 
  • For a series of antitumor-active 5-substituted 9-aminoacridine-4-carboxamide topoisomerase II poisons, we have used X-ray crystallography and stopped-flow spectrophotometry to explore relationships between DNA binding kinetics, biological activity, a ...

    For a series of antitumor-active 5-substituted 9-aminoacridine-4-carboxamide topoisomerase II poisons, we have used X-ray crystallography and stopped-flow spectrophotometry to explore relationships between DNA binding kinetics, biological activity, and the structures of their DNA complexes. The structure of 5-F-9-amino-[N-(2-dimethylamino)ethyl]-acridine-4-carboxamide bound to d(CGTACG)(2) has been solved to a resolution of 1.55 A in space group P6(4). A drug molecule intercalates between each of the CpG dinucleotide steps, its protonated dimethylamino group partially occupying positions close to the N7 and O6 atoms of guanine G2 in the major groove. A water molecule forms bridging hydrogen bonds between the 4-carboxamide NH and the phosphate group of the same guanine. Intercalation unwinds steps 1 and 2 by 12 degrees and 8 degrees, respectively compared with B-DNA, whereas the central TpA step is overwound by 10 degrees. Nonphenyl 5-substituents, on average, decrease mean DNA dissociation rates by a factor of three, regardless of their steric, hydrophobic, H-bonding, or electronic properties. Cytotoxicity is enhanced on average 4-fold and binding affinities rise by 3-fold, thus there is an apparent association between kinetics, affinity, and cytotoxicity. Taken together, the structural and kinetic studies imply that the main origin of this association is enhanced stacking interactions between the 5-substituent and cytosine in the CpG binding site. Ligand-dependent perturbations in base pair twist angles and their consequent effects on base pair-base pair stacking interactions may also contribute to the stability of the intercalated complex. 5-Phenyl substituents modify dissociation rates without affecting affinities, and variations in their biological activity are not correlated with DNA binding properties, which suggests that they interact directly with the topoisomerase protein.


    Organizational Affiliation

    Department of Biochemistry, University of Sydney, New South Wales, Australia. a.adams@biochem.usyd.edu.au




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsLengthOrganism
DNA (5'-D(*CP*GP*TP*AP*CP*G)-3')A6N/A
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
DA7
Query on DA7

Download SDF File 
Download CCD File 
A
5-FLUORO-9-AMINO-(N-(2-DIMETHYLAMINO)ETHYL)ACRIDINE-4-CARBOXAMIDE
C18 H19 F N4 O
QEHXKZSBSOBCGM-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.214 
  • Space Group: P 64
Unit Cell:
Length (Å)Angle (°)
a = 30.140α = 90.00
b = 30.140β = 90.00
c = 39.400γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
SHELXL-97refinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-10-30
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance