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ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements
Bacillus subtilis ParB forms multimeric networks involving non-specific DNA binding leading to DNA condensation. Previously, we found that an excess of the free C-terminal domain (CTD) of ParB impeded DNA condensation or promoted decondensation of pre-assembled networks (Fisher et al., 2017). Howeve...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6433461/ https://www.ncbi.nlm.nih.gov/pubmed/30907359 http://dx.doi.org/10.7554/eLife.43812 |
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author | Madariaga-Marcos, Julene Pastrana, Cesar L Fisher, Gemma LM Dillingham, Mark Simon Moreno-Herrero, Fernando |
author_facet | Madariaga-Marcos, Julene Pastrana, Cesar L Fisher, Gemma LM Dillingham, Mark Simon Moreno-Herrero, Fernando |
author_sort | Madariaga-Marcos, Julene |
collection | PubMed |
description | Bacillus subtilis ParB forms multimeric networks involving non-specific DNA binding leading to DNA condensation. Previously, we found that an excess of the free C-terminal domain (CTD) of ParB impeded DNA condensation or promoted decondensation of pre-assembled networks (Fisher et al., 2017). However, interpretation of the molecular basis for this phenomenon was complicated by our inability to uncouple protein binding from DNA condensation. Here, we have combined lateral magnetic tweezers with TIRF microscopy to simultaneously control the restrictive force against condensation and to visualise ParB protein binding by fluorescence. At non-permissive forces for condensation, ParB binds non-specifically and highly dynamically to DNA. Our new approach concluded that the free CTD blocks the formation of ParB networks by heterodimerisation with full length DNA-bound ParB. This strongly supports a model in which the CTD acts as a key bridging interface between distal DNA binding loci within ParB networks. |
format | Online Article Text |
id | pubmed-6433461 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-64334612019-03-27 ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements Madariaga-Marcos, Julene Pastrana, Cesar L Fisher, Gemma LM Dillingham, Mark Simon Moreno-Herrero, Fernando eLife Chromosomes and Gene Expression Bacillus subtilis ParB forms multimeric networks involving non-specific DNA binding leading to DNA condensation. Previously, we found that an excess of the free C-terminal domain (CTD) of ParB impeded DNA condensation or promoted decondensation of pre-assembled networks (Fisher et al., 2017). However, interpretation of the molecular basis for this phenomenon was complicated by our inability to uncouple protein binding from DNA condensation. Here, we have combined lateral magnetic tweezers with TIRF microscopy to simultaneously control the restrictive force against condensation and to visualise ParB protein binding by fluorescence. At non-permissive forces for condensation, ParB binds non-specifically and highly dynamically to DNA. Our new approach concluded that the free CTD blocks the formation of ParB networks by heterodimerisation with full length DNA-bound ParB. This strongly supports a model in which the CTD acts as a key bridging interface between distal DNA binding loci within ParB networks. eLife Sciences Publications, Ltd 2019-03-25 /pmc/articles/PMC6433461/ /pubmed/30907359 http://dx.doi.org/10.7554/eLife.43812 Text en © 2019, Madariaga-Marcos 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 Madariaga-Marcos, Julene Pastrana, Cesar L Fisher, Gemma LM Dillingham, Mark Simon Moreno-Herrero, Fernando ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements |
title | ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements |
title_full | ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements |
title_fullStr | ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements |
title_full_unstemmed | ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements |
title_short | ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements |
title_sort | parb dynamics and the critical role of the ctd in dna condensation unveiled by combined force-fluorescence measurements |
topic | Chromosomes and Gene Expression |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6433461/ https://www.ncbi.nlm.nih.gov/pubmed/30907359 http://dx.doi.org/10.7554/eLife.43812 |
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