کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1997262 1065561 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The Mcm2-7 Complex Has In Vitro Helicase Activity
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
The Mcm2-7 Complex Has In Vitro Helicase Activity
چکیده انگلیسی

SummaryHelicases unwind duplex DNA ahead of the polymerases at the replication fork. However, the identity of the eukaryotic replicative helicase has been controversial; in vivo studies implicate the ring-shaped heterohexameric Mcm2-7 complex, although only a specific subset of Mcm subunits (Mcm467) unwind DNA in vitro. To address this discrepancy, we have compared both Mcm assemblies and find that they differ in their linear single-stranded DNA association rate and their ability to bind circular single-stranded DNA. These differences depend upon the Mcm2/5 interface, which we hypothesize serves as an ATP-dependent “gate” within Mcm2-7. Importantly, we find that reaction conditions that putatively close the Mcm2-7 “gate” reconstitute Mcm2-7 helicase activity. Unlike Mcm467, Mcm2-7 helicase activity is strongly anion dependent. Our results show that purified Mcm2-7 acts as a helicase, provides functional evidence of a Mcm2/5 gate, and lays the foundation for future mechanistic studies of this critical factor.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 31, Issue 2, 25 July 2008, Pages 287–293
نویسندگان
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