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Published on: November 10, 2016
Induction of DNA replication-mediated double strand breaks by psoralen DNA interstrand cross-links
1Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245-3207, USA. besshot@uthscsa.edu
Abstract:
The effect of DNA interstrand cross-links (cross-links) on DNA replication was examined with a cell-free SV40 origin-dependent DNA replication system. A defined template DNA with a single psoralen cross-link and the SV40 origin of replication was replicated by HeLa cell-free extract in the presence of SV40 large T antigen. The psoralen cross-link inhibited DNA replication by terminating chain elongation at 1-50 nucleotides before the cross-linked sites. The termination of DNA replication by the cross-links mediated the generation of double strand breaks near the cross-linked sites. These results are the first biochemical evidence of the generation of double strand breaks by DNA replication.
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