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Assembly of Nucleosomal Arrays from Recombinant Core Histones and Nucleosome Positioning DNA
Published on: September 10, 2013
Crystal structures of nucleosome core particles containing the '601' strong positioning sequence
Dileep Vasudevan1, Eugene Y D Chua1, Curt A Davey1
1Division of Structural and Computational Biology, School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
Journal of Molecular Biology
|August 31, 2010
Summary
Nucleosome positioning is crucial for gene regulation. This study reveals how specific DNA sequences, like the
Area of Science:
- Structural Biology
- Genomics
- Molecular Biology
Background:
- Nucleosome positioning dictates DNA accessibility and influences molecular interactions.
- Understanding DNA sequence dependence in nucleosome positioning is key to chromatin structure.
- Previous nucleosome core particle (NCP) crystal structures relied on specific human DNA sequences.
Purpose of the Study:
- To elucidate the structural basis of nucleosome positioning using the strong '601' DNA sequence.
- To investigate the DNA sequence dependence of nucleosome structure and DNA mechanics.
- To enable the acquisition of diverse NCP crystal structures.
Main Methods:
- X-ray crystallography of Xenopus nucleosome core particles (NCPs) with '601' DNA.
- Analysis of histone-DNA interactions and DNA structural deformations.
- Comparison with previously determined NCP structures.
Main Results:
- Two crystal forms of Xenopus NCPs with '601' DNA revealed a consistent histone-DNA register.
- DNA stretching and overtwisting were observed near the nucleosome ends, increasing effective DNA length to 147 bp.
- Terminal DNA stretching correlated with minor groove kinking at purine-purine/pyrimidine-pyrimidine dinucleotide steps.
Conclusions:
- DNA stretching within nucleosomes is an intrinsic, sequence-specific property.
- Specific DNA sequence features dictate nucleosome structure and DNA deformability.
- These findings provide insights into obtaining NCP crystal structures with varied DNA sequences.
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