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Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences

The efficiency of horizontal gene transfer, which contributes to acquisition and spread of antibiotic resistance and pathogenicity traits, depends on nucleotide sequence and different mismatch-repair (MMR) proteins participate in this process. To study how MutL and MutS MMR proteins regulate recombi...

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Autores principales: Carrasco, Begoña, Serrano, Ester, Martín-González, Alejandro, Moreno-Herrero, Fernando, Alonso, Juan C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6382021/
https://www.ncbi.nlm.nih.gov/pubmed/30814990
http://dx.doi.org/10.3389/fmicb.2019.00237
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author Carrasco, Begoña
Serrano, Ester
Martín-González, Alejandro
Moreno-Herrero, Fernando
Alonso, Juan C.
author_facet Carrasco, Begoña
Serrano, Ester
Martín-González, Alejandro
Moreno-Herrero, Fernando
Alonso, Juan C.
author_sort Carrasco, Begoña
collection PubMed
description The efficiency of horizontal gene transfer, which contributes to acquisition and spread of antibiotic resistance and pathogenicity traits, depends on nucleotide sequence and different mismatch-repair (MMR) proteins participate in this process. To study how MutL and MutS MMR proteins regulate recombination across species boundaries, we have studied natural chromosomal transformation with DNA up to ∼23% sequence divergence. We show that Bacillus subtilis natural chromosomal transformation decreased logarithmically with increased sequence divergence up to 15% in wild type (wt) cells or in cells lacking MutS2 or mismatch repair proteins (MutL, MutS or both). Beyond 15% sequence divergence, the chromosomal transformation efficiency is ∼100-fold higher in ΔmutS and ΔmutSL than in ΔmutS2 or wt cells. In the first phase of the biphasic curve (up to 15% sequence divergence), RecA-catalyzed DNA strand exchange contributes to the delineation of species, and in the second phase, homology-facilitated illegitimate recombination might aid in the restoration of inactivated genes. To understand how MutS modulates the integration process, we monitored DNA strand exchange reactions using a circular single-stranded DNA and a linear double-stranded DNA substrate with an internal 77-bp region with ∼16% or ∼54% sequence divergence in an otherwise homologous substrate. The former substrate delayed, whereas the latter halted RecA-mediated strand exchange. Interestingly, MutS addition overcame the heterologous barrier. We propose that MutS assists DNA strand exchange by facilitating RecA disassembly, and indirectly re-engagement with the homologous 5′-end of the linear duplex. Our data supports the idea that MutS modulates bidirectional RecA-mediated integration of divergent sequences and this is important for speciation.
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spelling pubmed-63820212019-02-27 Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences Carrasco, Begoña Serrano, Ester Martín-González, Alejandro Moreno-Herrero, Fernando Alonso, Juan C. Front Microbiol Microbiology The efficiency of horizontal gene transfer, which contributes to acquisition and spread of antibiotic resistance and pathogenicity traits, depends on nucleotide sequence and different mismatch-repair (MMR) proteins participate in this process. To study how MutL and MutS MMR proteins regulate recombination across species boundaries, we have studied natural chromosomal transformation with DNA up to ∼23% sequence divergence. We show that Bacillus subtilis natural chromosomal transformation decreased logarithmically with increased sequence divergence up to 15% in wild type (wt) cells or in cells lacking MutS2 or mismatch repair proteins (MutL, MutS or both). Beyond 15% sequence divergence, the chromosomal transformation efficiency is ∼100-fold higher in ΔmutS and ΔmutSL than in ΔmutS2 or wt cells. In the first phase of the biphasic curve (up to 15% sequence divergence), RecA-catalyzed DNA strand exchange contributes to the delineation of species, and in the second phase, homology-facilitated illegitimate recombination might aid in the restoration of inactivated genes. To understand how MutS modulates the integration process, we monitored DNA strand exchange reactions using a circular single-stranded DNA and a linear double-stranded DNA substrate with an internal 77-bp region with ∼16% or ∼54% sequence divergence in an otherwise homologous substrate. The former substrate delayed, whereas the latter halted RecA-mediated strand exchange. Interestingly, MutS addition overcame the heterologous barrier. We propose that MutS assists DNA strand exchange by facilitating RecA disassembly, and indirectly re-engagement with the homologous 5′-end of the linear duplex. Our data supports the idea that MutS modulates bidirectional RecA-mediated integration of divergent sequences and this is important for speciation. Frontiers Media S.A. 2019-02-13 /pmc/articles/PMC6382021/ /pubmed/30814990 http://dx.doi.org/10.3389/fmicb.2019.00237 Text en Copyright © 2019 Carrasco, Serrano, Martín-González, Moreno-Herrero and Alonso. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Carrasco, Begoña
Serrano, Ester
Martín-González, Alejandro
Moreno-Herrero, Fernando
Alonso, Juan C.
Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences
title Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences
title_full Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences
title_fullStr Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences
title_full_unstemmed Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences
title_short Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences
title_sort bacillus subtilis muts modulates reca-mediated dna strand exchange between divergent dna sequences
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6382021/
https://www.ncbi.nlm.nih.gov/pubmed/30814990
http://dx.doi.org/10.3389/fmicb.2019.00237
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