1fhy
PSORALEN CROSS-LINKED D(CCGCTAGCGG) FORMS HOLLIDAY JUNCTION
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OverviewOverview
The single-crystal structures are presented for two DNA sequences with the, thymine bases covalently cross-linked across the complementary strands by, 4'-hydroxymethyl-4,5',8-trimethylpsoralen (HMT). The HMT-adduct of, d(CCGCTAGCGG) forms a psoralen-induced Holliday junction, showing for the, first time the effect of this important class of chemotheraputics on the, structure of the recombination intermediate. In contrast, HMT-d(CCGGTACCGG) forms a sequence-dependent junction. In both structures, the DNA duplex is highly distorted at the thymine base linked to the, six-member pyrone ring of the drug. The psoralen cross-link defines the, intramolecular interactions of the drug-induced junction, while the, sequence-dependent structure is nearly identical to the native Holliday, junction of d(CCGGTACCGG) alone. The two structures contrast the effects, of drug- and sequence-dependent interactions on the structure of a, Holliday junction, suggesting a role for psoralen in the mechanism to, initiate repair of psoralen-lesions in mammalian DNA.
About this StructureAbout this Structure
1FHY is a Protein complex structure of sequences from [1] with CA and PSO as ligands. Full crystallographic information is available from OCA.
ReferenceReference
The crystal structures of psoralen cross-linked DNAs: drug-dependent formation of Holliday junctions., Eichman BF, Mooers BH, Alberti M, Hearst JE, Ho PS, J Mol Biol. 2001 Apr 20;308(1):15-26. PMID:11302703
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