Surprising Twists in Nucleosomal DNA with Implication for Higher-order Folding
| Autor: | Stefjord Todolli, Abigail S. Watkins, John Yager, Wilma K. Olson, Antonio Bu Sha, Robert T. Young |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Physics
Models Molecular biology Nucleosome disassembly DNA Folding computer.file_format DNA Protein Data Bank Chromatin Assembly and Disassembly Article Nucleosomes Folding (chemistry) Histones chemistry.chemical_compound Histone chemistry Structural Biology biology.protein Nucleosome Nucleic Acid Conformation Statistical physics Twist Molecular Biology computer |
| Zdroj: | J Mol Biol |
| Popis: | While nucleosomes are dynamic entities that must undergo structural deformations to perform their functions, the general view from available high-resolution structures is a largely static one. Even though numerous examples of twist defects have been documented, the DNA wrapped around the histone core is generally thought to be overtwisted. Analysis of available high-resolution structures from the Protein Data Bank reveals a heterogeneous distribution of twist along the nucleosomal DNA, with clear patterns that are consistent with the literature, and a significant fraction of structures that are undertwisted. The subtle differences in nucleosomal DNA folding, which extend beyond twist, have implications for nucleosome disassembly and modeled higher-order structures. Simulations of oligonucleosome arrays built with undertwisted models behave very differently from those constructed from overtwisted models, in terms of compaction and inter-nucleosome contacts, introducing configurational changes equivalent to those associated with 2-3 base-pair changes in nucleosome spacing. Differences in the nucleosomal DNA pathway, which underlie the way that DNA enters and exits the nucleosome, give rise to different nucleosome-decorated minicircles and affect the topological mix of configurational states. |
| Databáze: | OpenAIRE |
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