Short nucleosome repeats impose rotational modulations on chromatin fibre folding

In eukaryotic cells, DNA is organized into arrays of repeated nucleosomes where the shorter nucleosome repeat length (NRL) types are associated with transcriptionally active chromatin. Here, we tested a hypothesis that systematic variations in the NRL influence nucleosome array folding into higher‐o...

Full description

Saved in:
Bibliographic Details
Published in:The EMBO journal 2012-05, Vol.31 (10), p.2416-2426
Main Authors: Correll, Sarah J, Schubert, Michaela H, Grigoryev, Sergei A
Format: Article
Language:English
Subjects:
Cellular biology
Chromatin
Chromatin - metabolism
Chromatin - ultrastructure
chromatin fibre
Deoxyribonucleic acid
DNA
DNA, Fungal - metabolism
DNA, Fungal - ultrastructure
EMBO09
higher-order structure
linker DNA
linker histone
Microscopy, Electron
Models, Molecular
Molecular biology
nucleosome
Nucleosomes - metabolism
Nucleosomes - ultrastructure
Protein folding
Yeasts
Yeasts - metabolism
Yeasts - physiology
Yeasts - ultrastructure
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In eukaryotic cells, DNA is organized into arrays of repeated nucleosomes where the shorter nucleosome repeat length (NRL) types are associated with transcriptionally active chromatin. Here, we tested a hypothesis that systematic variations in the NRL influence nucleosome array folding into higher‐order structures. For NRLs with fixed rotational settings, we observed a negative correlation between NRL and chromatin folding. Rotational variations within a range of longer NRLs (188 bp and above) typical of repressed chromatin in differentiated cells did not reveal any changes in chromatin folding. In sharp contrast, for the shorter NRL range of 165–177 bp, we observed a strong periodic dependence of chromatin folding upon the changes in linker DNA lengths, with the 172 bp repeat found in highly transcribed yeast chromatin imposing an unfolded state of the chromatin fibre that could be reversed by linker histone. Our results suggest that the NRL may direct chromatin higher‐order structure into either a nucleosome position‐dependent folding for short NRLs typical of transcribed genes or an architectural factor‐dependent folding typical of longer NRLs prevailing in eukaryotic heterochromatin. Folding of nucleosome arrays into higher‐order structures depends on nucleosome repeat length and the total twist of linker DNA, supporting recent genome‐wide mappings of nucleosome positions.
ISSN:0261-4189
1460-2075
DOI:10.1038/emboj.2012.80