Chromatin remodelers are complexes able to both alter histone-DNA interactions and to mobilize nucleosomes. The mechanism of their action and the conformation of remodeled nucleosomes remain a matter of debates. In this work we compared the type and structure of the products of nucleosome remodeling by SWI/SNF and ACF complexes using high-resolution microscopy combined with novel biochemical approaches. We find that SWI/SNF generates a multitude of nucleosome-like metastable particles termed "remosomes". Restriction enzyme accessibility assay, DNase I footprinting and AFM experiments reveal perturbed histone-DNA interactions within these particles. Electron cryo-microscopy shows that remosomes adopt a variety of different structures with variable irregular DNA path, similar to those described upon RSC remodeling. Remosome DNA accessibility to restriction enzymes is also markedly increased. We suggest that the generation of remosomes is a common feature of the SWI/SNF family remodelers. In contrast, the ACF remodeler, belonging to ISWI family, only produces repositioned nucleosomes and no evidence for particles associated with extra DNA, or perturbed DNA paths was found. The remosome generation by the SWI/SNF type of remodelers may represent a novel mechanism involved in processes where nucleosomal DNA accessibility is required, such as DNA repair or transcription regulation.

• MeSH
• adenosintrifosfát metabolismus   farmakologie   MeSH
• bezbuněčný systém MeSH
• chromozomální proteiny, nehistonové fyziologie   MeSH
• DNA bakterií metabolismus   MeSH
• DNA footprinting MeSH
• fungální proteiny fyziologie   MeSH
• histony genetika   metabolismus   MeSH
• mikroskopie atomárních sil MeSH
• multiproteinové komplexy fyziologie   MeSH
• nukleozomy fyziologie   ultrastruktura   MeSH
• plazmidy chemie   MeSH
• proteiny vázající RNA fyziologie   MeSH
• rekombinantní proteiny metabolismus   MeSH
• restrikční endonukleasy typu II MeSH
• restrukturace chromatinu genetika   fyziologie   MeSH
• Saccharomyces cerevisiae metabolismus   ultrastruktura   MeSH
• Xenopus laevis genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH