Sequence-specific photo-induced cross-linking of the two strands of double-helical DNA by a psoralen covalently linked to a triple helix-forming oligonucleotide.
AUTOR(ES)
Takasugi, M
RESUMO
On the basis of the structure of DNA-psoralen bis adducts (formed by psoralen with two thymines on opposite strands), a psoralen-oligonucleotide conjugate was designed to photoinduce a cross-link between the two DNA strands at a specific sequence. Psoralen was attached via its C-5 position to a 5'-thiophosphate group of an 11-mer homopyrimidine oligonucleotide. The 11-mer binds to an 11-base-pair homopurine.homopyrimidine sequence of a DNA fragment, where it forms a triple helix. Upon near-UV-irradiation, the two strands of DNA are crosslinked at the TpA step present at the triplex-duplex junction. The reaction is specific for the homopurine.homopyrimidine DNA sequence and requires both oligonucleotide recognition of the DNA major groove and intercalation of psoralen at the triplex-duplex junction. The yield of the photo-induced cross-linking reaction is quite high (greater than 80%). Such psoralen-oligonucleotide conjugates are probes of sequence-specific triple-helix formation and could be used to selectively control gene expression or to induce site-directed mutations.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=51925Documentos Relacionados
- Oligodeoxynucleotide-directed photo-induced cross-linking of HIV proviral DNA via triple-helix formation.
- Targeted mutagenesis of DNA using triple helix-forming oligonucleotides linked to psoralen.
- Targeted mutagenesis of simian virus 40 DNA mediated by a triple helix-forming oligonucleotide.
- Covalent crosslinks introduced via a triple helix-forming oligonucleotide coupled to psoralen are inefficiently repaired.
- Site-specific targeting of psoralen photoadducts with a triple helix-forming oligonucleotide: characterization of psoralen monoadduct and crosslink formation.
