کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2147094 1548397 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
RecQ and RecG helicases have distinct roles in maintaining the stability of polypurine·polypyrimidine sequences
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی تحقیقات سرطان
پیش نمایش صفحه اول مقاله
RecQ and RecG helicases have distinct roles in maintaining the stability of polypurine·polypyrimidine sequences
چکیده انگلیسی
DNA triplex structures can block the replication fork and result in double-stranded DNA breaks (DSBs). RecQ and RecG helicases may be important for replication of such sequences as RecQ resolves synthetic triplex DNA structures and RecG mediates replication restart by fork regression. Primer extension on an 88 bp triplex-forming polypurine·polypyrimidine (Pu·Py) tract from the PKD1 gene demonstrated that RecQ, but not RecG, facilitated primer extension by T7 DNA polymerase. A high-throughput, dual plasmid screening system using isogenic bacterial lines deficient in RecG, RecQ, or both, revealed that RecQ deficiency increased mutation to sequence flanking this 88 bp tract by eight to ten-fold. Although RecG facilitated small deletions in an 88 bp mirror repeat-containing sequence, it was absolutely required to maintain a 2.5 kb Pu·Py tract containing multiple mirror repeats. These results support a two-tiered model where RecQ facilitates fork progression through triplex-forming tracts and, failing processivity, RecG is critical for replication fork restart.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis - Volume 643, Issues 1–2, 25 August 2008, Pages 20-28
نویسندگان
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