کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1997940 1065630 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Architecture of a Polycomb Nucleoprotein Complex
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Architecture of a Polycomb Nucleoprotein Complex
چکیده انگلیسی

SummaryPolycomb group (PcG) epigenetic silencing proteins act through cis-acting DNA sequences, named Polycomb response elements (PREs). Within PREs, Pleiohomeotic (PHO) binding sites and juxtaposed Pc binding elements (PBEs) function as an integrated DNA platform for the synergistic binding of PHO and the multisubunit Polycomb core complex (PCC). Here, we analyzed the architecture of the PHO/PCC/PRE nucleoprotein complex. DNase I footprinting revealed extensive contacts between PHO/PCC and the PRE. Scanning force microscopy (SFM) in combination with DNA topological assays suggested that PHO/PCC wraps the PRE DNA around its surface in a constrained negative supercoil. These features are difficult to reconcile with the simultaneous presence of nucleosomes at the PRE. Indeed, chromatin immunoprecipitations (ChIPs) and nuclease mapping demonstrated that PREs are nucleosome depleted in vivo. We discuss the implications of these findings for models explaining PRE function.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 24, Issue 1, 6 October 2006, Pages 91–100
نویسندگان
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