Solution structure of a cisplatin-induced DNA interstrand cross-link.
The widely used antitumor drug cis-diamminedichloroplatinum(II) (cisplatin or cis-DDP) reacts with DNA, cross-linking two purine residues through the N7 atoms, which reside in the major groove in B-form DNA. The solution structure of the short duplex [d(CAT-AGCTATG)]2 cross-linked at the GC:GC site was determined by nuclear magnetic resonance (NMR). The deoxyguanosine-bridging cis-diammineplatinum(II) lies in the minor groove, and the complementary deoxycytidines are extrahelical. The double helix is locally reversed to a left-handed form, and the helix is unwound and bent toward the minor groove. These findings were independently confirmed by results from a phase-sensitive gel electrophoresis bending assay. The NMR structure differs markedly from previously proposed models but accounts for the chemical reactivity, the unwinding, and the bending of cis-DDP interstrand cross-linked DNA and may be important in the formation and repair of these cross-links in chromatin.
Huang
H
H
Department of Chemistry, University of Washington, Seattle 98195, USA.
Zhu
L
L
Reid
B R
BR
Drobny
G P
GP
Hopkins
P B
PB
D000970:Antineoplastic Agents / Q000494:pharmacology*; D001483:Base Sequence; D002945:Cisplatin / Q000494:pharmacology*; D004247:DNA / Q000737:chemistry* / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012996:Solutions
D000970:Antineoplastic Agents; D012996:Solutions; D004247:DNA; D002945:Cisplatin