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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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2019-02-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fmicb.2019.00237/full |
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| author | Begoña Carrasco Ester Serrano Alejandro Martín-González Fernando Moreno-Herrero Juan C. Alonso |
| author_facet | Begoña Carrasco Ester Serrano Alejandro Martín-González Fernando Moreno-Herrero Juan C. Alonso |
| author_sort | Begoña Carrasco |
| collection | DOAJ |
| 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. |
| first_indexed | 2024-12-23T21:34:37Z |
| format | Article |
| id | doaj.art-6287b623bf5c45749f71308ffd024dbb |
| institution | Directory Open Access Journal |
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| language | English |
| last_indexed | 2024-12-23T21:34:37Z |
| publishDate | 2019-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-6287b623bf5c45749f71308ffd024dbb2022-12-21T17:30:20ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2019-02-011010.3389/fmicb.2019.00237439469Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA SequencesBegoña Carrasco0Ester Serrano1Alejandro Martín-González2Fernando Moreno-Herrero3Juan C. Alonso4Department of Microbial Biotechnology, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, SpainDepartment of Microbial Biotechnology, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, SpainDepartment of Macromolecular Structures, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, SpainDepartment of Macromolecular Structures, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, SpainDepartment of Microbial Biotechnology, Centro Nacional de Biotecnología – Consejo Superior de Investigaciones Científicas, Madrid, SpainThe 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.https://www.frontiersin.org/article/10.3389/fmicb.2019.00237/fullhorizontal gene transfergenetic variationmismatch repairRecA nucleoprotein filamentsMutSSsbA |
| spellingShingle | Begoña Carrasco Ester Serrano Alejandro Martín-González Fernando Moreno-Herrero Juan C. Alonso Bacillus subtilis MutS Modulates RecA-Mediated DNA Strand Exchange Between Divergent DNA Sequences Frontiers in Microbiology horizontal gene transfer genetic variation mismatch repair RecA nucleoprotein filaments MutS SsbA |
| 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 | horizontal gene transfer genetic variation mismatch repair RecA nucleoprotein filaments MutS SsbA |
| url | https://www.frontiersin.org/article/10.3389/fmicb.2019.00237/full |
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