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Zinc is an inhibitor of the LdtR transcriptional activator

LdtR is a master regulator of gene expression in Liberibacter asiaticus, one of the causative agents of citrus greening disease. LdtR belongs to the MarR-family of transcriptional regulators and it has been linked to the regulation of more than 180 genes in Liberibacter species, most of them gathere...

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Autores principales: Pagliai, Fernando A., Pan, Lei, Silva, Danilo, Gonzalez, Claudio F., Lorca, Graciela L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5892913/
https://www.ncbi.nlm.nih.gov/pubmed/29634775
http://dx.doi.org/10.1371/journal.pone.0195746
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author Pagliai, Fernando A.
Pan, Lei
Silva, Danilo
Gonzalez, Claudio F.
Lorca, Graciela L.
author_facet Pagliai, Fernando A.
Pan, Lei
Silva, Danilo
Gonzalez, Claudio F.
Lorca, Graciela L.
author_sort Pagliai, Fernando A.
collection PubMed
description LdtR is a master regulator of gene expression in Liberibacter asiaticus, one of the causative agents of citrus greening disease. LdtR belongs to the MarR-family of transcriptional regulators and it has been linked to the regulation of more than 180 genes in Liberibacter species, most of them gathered in the following Clusters of Orthologous Groups: cell motility, cell wall envelope, energy production, and transcription. Our previous transcriptomic evidence suggested that LdtR is directly involved in the modulation of the zinc uptake system genes (znu) in the closely related L. crescens. In this report, we show that LdtR is involved in the regulation of one of the two encoded zinc uptake mechanisms in L. asiaticus, named znu(2). We also show that LdtR binds zinc with higher affinity than benzbromarone, a synthetic effector inhibitory molecule, resulting in the disruption of the LdtR:promoter interactions. Using site-directed mutagenesis, electrophoretic mobility shift assays (EMSAs), and isothermal titration calorimetry, we identified that residues C28 and T43 in LdtR, located in close proximity to the Benz1 pocket, are involved in the interaction with zinc. These results provided new evidence of a high-affinity effector molecule targeting a key player in L. asiaticus’ physiology and complemented our previous findings about the mechanisms of signal transduction in members of the MarR-family.
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spelling pubmed-58929132018-04-20 Zinc is an inhibitor of the LdtR transcriptional activator Pagliai, Fernando A. Pan, Lei Silva, Danilo Gonzalez, Claudio F. Lorca, Graciela L. PLoS One Research Article LdtR is a master regulator of gene expression in Liberibacter asiaticus, one of the causative agents of citrus greening disease. LdtR belongs to the MarR-family of transcriptional regulators and it has been linked to the regulation of more than 180 genes in Liberibacter species, most of them gathered in the following Clusters of Orthologous Groups: cell motility, cell wall envelope, energy production, and transcription. Our previous transcriptomic evidence suggested that LdtR is directly involved in the modulation of the zinc uptake system genes (znu) in the closely related L. crescens. In this report, we show that LdtR is involved in the regulation of one of the two encoded zinc uptake mechanisms in L. asiaticus, named znu(2). We also show that LdtR binds zinc with higher affinity than benzbromarone, a synthetic effector inhibitory molecule, resulting in the disruption of the LdtR:promoter interactions. Using site-directed mutagenesis, electrophoretic mobility shift assays (EMSAs), and isothermal titration calorimetry, we identified that residues C28 and T43 in LdtR, located in close proximity to the Benz1 pocket, are involved in the interaction with zinc. These results provided new evidence of a high-affinity effector molecule targeting a key player in L. asiaticus’ physiology and complemented our previous findings about the mechanisms of signal transduction in members of the MarR-family. Public Library of Science 2018-04-10 /pmc/articles/PMC5892913/ /pubmed/29634775 http://dx.doi.org/10.1371/journal.pone.0195746 Text en © 2018 Pagliai et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Pagliai, Fernando A.
Pan, Lei
Silva, Danilo
Gonzalez, Claudio F.
Lorca, Graciela L.
Zinc is an inhibitor of the LdtR transcriptional activator
title Zinc is an inhibitor of the LdtR transcriptional activator
title_full Zinc is an inhibitor of the LdtR transcriptional activator
title_fullStr Zinc is an inhibitor of the LdtR transcriptional activator
title_full_unstemmed Zinc is an inhibitor of the LdtR transcriptional activator
title_short Zinc is an inhibitor of the LdtR transcriptional activator
title_sort zinc is an inhibitor of the ldtr transcriptional activator
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5892913/
https://www.ncbi.nlm.nih.gov/pubmed/29634775
http://dx.doi.org/10.1371/journal.pone.0195746
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