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Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer

The MOB(V1) family of relaxases is broadly distributed in plasmids and other mobile genetic elements isolated from staphylococci, enterococci, and streptococci. The prototype of this family is protein MobM encoded by the streptococcal promiscuous plasmid pMV158. MobM cleaves the phosphodiester bond...

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Autores principales: Lorenzo-Díaz, Fabián, Fernández-López, Cris, Guillén-Guío, Beatriz, Bravo, Alicia, Espinosa, Manuel
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5863519/
https://www.ncbi.nlm.nih.gov/pubmed/29600250
http://dx.doi.org/10.3389/fmolb.2018.00017
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author Lorenzo-Díaz, Fabián
Fernández-López, Cris
Guillén-Guío, Beatriz
Bravo, Alicia
Espinosa, Manuel
author_facet Lorenzo-Díaz, Fabián
Fernández-López, Cris
Guillén-Guío, Beatriz
Bravo, Alicia
Espinosa, Manuel
author_sort Lorenzo-Díaz, Fabián
collection PubMed
description The MOB(V1) family of relaxases is broadly distributed in plasmids and other mobile genetic elements isolated from staphylococci, enterococci, and streptococci. The prototype of this family is protein MobM encoded by the streptococcal promiscuous plasmid pMV158. MobM cleaves the phosphodiester bond of a specific dinucleotide within the origin of transfer (oriT) to initiate conjugative transfer. Differently from other relaxases, MobM and probably other members of the family, cleaves its target single-stranded DNA through a histidine residue rather than the commonly used tyrosine. The oriT of the MOB(V1) family differs from other well-known conjugative systems since it has sequences with three inverted repeats, which were predicted to generate three mutually-exclusive hairpins on supercoiled DNA. In this work, such hypothesis was evaluated through footprinting experiments on supercoiled plasmid DNA. We have found a change in hairpin extrusion mediated by protein MobM. This conformational change involves a shift from the main hairpin generated on “naked” DNA to a different hairpin in which the nick site is positioned in a single-stranded configuration. Our results indicate that the oriT(pMV158) acts as a molecular switch in which, depending on the inverted repeat recognized by MobM, pMV158 mobilization could be turned “on” or “off.”
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spelling pubmed-58635192018-03-29 Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer Lorenzo-Díaz, Fabián Fernández-López, Cris Guillén-Guío, Beatriz Bravo, Alicia Espinosa, Manuel Front Mol Biosci Molecular Biosciences The MOB(V1) family of relaxases is broadly distributed in plasmids and other mobile genetic elements isolated from staphylococci, enterococci, and streptococci. The prototype of this family is protein MobM encoded by the streptococcal promiscuous plasmid pMV158. MobM cleaves the phosphodiester bond of a specific dinucleotide within the origin of transfer (oriT) to initiate conjugative transfer. Differently from other relaxases, MobM and probably other members of the family, cleaves its target single-stranded DNA through a histidine residue rather than the commonly used tyrosine. The oriT of the MOB(V1) family differs from other well-known conjugative systems since it has sequences with three inverted repeats, which were predicted to generate three mutually-exclusive hairpins on supercoiled DNA. In this work, such hypothesis was evaluated through footprinting experiments on supercoiled plasmid DNA. We have found a change in hairpin extrusion mediated by protein MobM. This conformational change involves a shift from the main hairpin generated on “naked” DNA to a different hairpin in which the nick site is positioned in a single-stranded configuration. Our results indicate that the oriT(pMV158) acts as a molecular switch in which, depending on the inverted repeat recognized by MobM, pMV158 mobilization could be turned “on” or “off.” Frontiers Media S.A. 2018-02-26 /pmc/articles/PMC5863519/ /pubmed/29600250 http://dx.doi.org/10.3389/fmolb.2018.00017 Text en Copyright © 2018 Lorenzo-Díaz, Fernández-López, Guillén-Guío, Bravo and Espinosa. 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 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 Molecular Biosciences
Lorenzo-Díaz, Fabián
Fernández-López, Cris
Guillén-Guío, Beatriz
Bravo, Alicia
Espinosa, Manuel
Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer
title Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer
title_full Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer
title_fullStr Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer
title_full_unstemmed Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer
title_short Relaxase MobM Induces a Molecular Switch at Its Cognate Origin of Transfer
title_sort relaxase mobm induces a molecular switch at its cognate origin of transfer
topic Molecular Biosciences
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5863519/
https://www.ncbi.nlm.nih.gov/pubmed/29600250
http://dx.doi.org/10.3389/fmolb.2018.00017
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