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Assembly of Nucleosomal Arrays from Recombinant Core Histones and Nucleosome Positioning DNA
Published on: September 10, 2013
The core histone tail domains contribute to sequence-dependent nucleosome positioning
Zungyoon Yang1, Chunyang Zheng, Jeffrey J Hayes
1Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York 14642, USA.
The Journal of Biological Chemistry
|January 20, 2007
Summary
Histone tail domains influence where nucleosomes bind on DNA, affecting gene regulation. Removing these tails alters nucleosome positions on some DNA sequences, but not others, depending on DNA binding affinity.
Area of Science:
- Chromatin biology
- Molecular genetics
- Gene regulation
Background:
- Nucleosome positioning is crucial for gene expression regulation.
- The molecular basis for nucleosome positioning remains incompletely understood.
- Histone tail domains are implicated in chromatin structure and function.
Purpose of the Study:
- To investigate the role of core histone tail domains in nucleosome positioning.
- To determine if removal of histone tails alters nucleosome translational positions on specific DNA sequences.
- To elucidate the mechanism of sequence-dependent nucleosome positioning.
Main Methods:
- Reconstitution of nucleosomes with specific DNA fragments and core histone proteins.
- Experimental removal of core histone tail domains.
- Analysis of nucleosome translational positions along DNA using established techniques.
Main Results:
- Removal of histone tail domains caused nucleosome repositioning on DNA fragments containing Xenopus 5S RNA and Drosophila Adh genes.
- Nucleosome positions shifted approximately 20 bp upstream for the 5S RNA gene and 10 bp for the Adh gene promoter.
- Nucleosome positioning on high-affinity mouse genomic DNA was unaffected by tail removal.
- Histone tail removal facilitated easier movement between translational positions on certain DNA sequences.
Conclusions:
- Basic histone tail domains interact with nucleosomal DNA, influencing nucleosome translational positioning.
- The impact of histone tails on nucleosome positioning is DNA sequence-dependent.
- High-affinity DNA sequences can mask the effect of histone tails on positioning.
- Regulated changes in histone tail-DNA interactions offer a mechanism for altering sequence-dependent nucleosome positioning.
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