X-ray crystallographic study of DNA duplex cross-linking: simultaneous binding to two d(CGTACG)(2) molecules by a bis(9-aminoacridine-4-carboxamide) derivative

Hopcroft, N. H., Brogden, A. L., Searcey, M. and Cardin, C. J. ORCID: https://orcid.org/0000-0002-2556-9995 (2006) X-ray crystallographic study of DNA duplex cross-linking: simultaneous binding to two d(CGTACG)(2) molecules by a bis(9-aminoacridine-4-carboxamide) derivative. Nucleic Acids Research, 34 (22). pp. 6663-6672. ISSN 1362-4962 doi: 10.1093/nar/gkl930

Abstract/Summary

Acridine-4-carboxamides form a class of known DNA mono-intercalating agents that exhibit cytotoxic activity against tumour cell lines due to their ability to inhibit topoisomerases. Previous studies of bis-acridine derivatives have yielded equivocal results regarding the minimum length of linker necessary between the two acridine chromophores to allow bis-intercalation of duplex DNA. We report here the 1.7 angstrom resolution X-ray crystal structure of a six-carbon-linked bis(acridine-4-carboxamide) ligand bound to d(CGTACG)(2) molecules by non-covalent duplex cross-linking. The asymmetric unit consists of one DNA duplex containing an intercalated acridine-4-carboxamide chromophore at each of the two CG steps. The other half of each ligand is bound to another DNA molecule in a symmetry-related manner, with the alkyl linker threading through the minor grooves. The two crystallographically independent ligand molecules adopt distinct side chain interactions, forming hydrogen bonds to either O6 or N7 on the major groove face of guanine, in contrast to the semi-disordered state of mono-intercalators bound to the same DNA molecule. The complex described here provides the first structural evidence for the non-covalent cross-linking of DNA by a small molecule ligand and suggests a possible explanation for the inconsistent behaviour of six-carbon linked bis-acridines in previous assays of DNA bis-intercalation.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/11338
Identification Number/DOI	10.1093/nar/gkl930
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
Uncontrolled Keywords	ACRIDINECARBOXAMIDE TOPOISOMERASE POISONS, PROTEIN DATA-BANK, BIFUNCTIONAL INTERCALATION, 3-DIMENSIONAL STRUCTURES, DEOXYRIBONUCLEIC-ACID, CRYSTAL-STRUCTURE, COMPLEX, DIACRIDINES, BIS(ACRIDINES), ECHINOMYCIN
Publisher	Oxford University Press
Download/View statistics	View download statistics for this item