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Ion counting demonstrates a high electrostatic field generated by the nucleosome

In eukaryotes, a first step towards the nuclear DNA compaction process is the formation of a nucleosome, which is comprised of negatively charged DNA wrapped around a positively charged histone protein octamer. Often, it is assumed that the complexation of the DNA into the nucleosome completely atte...

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Autores principales: Gebala, Magdalena, Johnson, Stephanie L, Narlikar, Geeta J, Herschlag, Dan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: eLife Sciences Publications, Ltd 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6584128/
https://www.ncbi.nlm.nih.gov/pubmed/31184587
http://dx.doi.org/10.7554/eLife.44993
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author Gebala, Magdalena
Johnson, Stephanie L
Narlikar, Geeta J
Herschlag, Dan
author_facet Gebala, Magdalena
Johnson, Stephanie L
Narlikar, Geeta J
Herschlag, Dan
author_sort Gebala, Magdalena
collection PubMed
description In eukaryotes, a first step towards the nuclear DNA compaction process is the formation of a nucleosome, which is comprised of negatively charged DNA wrapped around a positively charged histone protein octamer. Often, it is assumed that the complexation of the DNA into the nucleosome completely attenuates the DNA charge and hence the electrostatic field generated by the molecule. In contrast, theoretical and computational studies suggest that the nucleosome retains a strong, negative electrostatic field. Despite their fundamental implications for chromatin organization and function, these opposing views of nucleosome electrostatics have not been experimentally tested. Herein, we directly measure nucleosome electrostatics and find that while nucleosome formation reduces the complex charge by half, the nucleosome nevertheless maintains a strong negative electrostatic field. Our studies highlight the importance of considering the polyelectrolyte nature of the nucleosome and its impact on processes ranging from factor binding to DNA compaction.
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spelling pubmed-65841282019-06-21 Ion counting demonstrates a high electrostatic field generated by the nucleosome Gebala, Magdalena Johnson, Stephanie L Narlikar, Geeta J Herschlag, Dan eLife Chromosomes and Gene Expression In eukaryotes, a first step towards the nuclear DNA compaction process is the formation of a nucleosome, which is comprised of negatively charged DNA wrapped around a positively charged histone protein octamer. Often, it is assumed that the complexation of the DNA into the nucleosome completely attenuates the DNA charge and hence the electrostatic field generated by the molecule. In contrast, theoretical and computational studies suggest that the nucleosome retains a strong, negative electrostatic field. Despite their fundamental implications for chromatin organization and function, these opposing views of nucleosome electrostatics have not been experimentally tested. Herein, we directly measure nucleosome electrostatics and find that while nucleosome formation reduces the complex charge by half, the nucleosome nevertheless maintains a strong negative electrostatic field. Our studies highlight the importance of considering the polyelectrolyte nature of the nucleosome and its impact on processes ranging from factor binding to DNA compaction. eLife Sciences Publications, Ltd 2019-06-11 /pmc/articles/PMC6584128/ /pubmed/31184587 http://dx.doi.org/10.7554/eLife.44993 Text en © 2019, Gebala et al http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited.
spellingShingle Chromosomes and Gene Expression
Gebala, Magdalena
Johnson, Stephanie L
Narlikar, Geeta J
Herschlag, Dan
Ion counting demonstrates a high electrostatic field generated by the nucleosome
title Ion counting demonstrates a high electrostatic field generated by the nucleosome
title_full Ion counting demonstrates a high electrostatic field generated by the nucleosome
title_fullStr Ion counting demonstrates a high electrostatic field generated by the nucleosome
title_full_unstemmed Ion counting demonstrates a high electrostatic field generated by the nucleosome
title_short Ion counting demonstrates a high electrostatic field generated by the nucleosome
title_sort ion counting demonstrates a high electrostatic field generated by the nucleosome
topic Chromosomes and Gene Expression
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6584128/
https://www.ncbi.nlm.nih.gov/pubmed/31184587
http://dx.doi.org/10.7554/eLife.44993
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AT herschlagdan ioncountingdemonstratesahighelectrostaticfieldgeneratedbythenucleosome