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A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis

During infection, pathogens are starved of essential nutrients such as iron and tryptophan by host immune effectors. Without conserved global stress response regulators, how the obligate intracellular bacterium Chlamydia trachomatis arrives at a physiologically similar ‘persistent’ state in response...

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Detalles Bibliográficos
Autores principales: Pokorzynski, Nick D, Brinkworth, Amanda J, Carabeo, Rey
Formato: Online Artículo Texto
Lenguaje:English
Publicado: eLife Sciences Publications, Ltd 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6504234/
https://www.ncbi.nlm.nih.gov/pubmed/30938288
http://dx.doi.org/10.7554/eLife.42295
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author Pokorzynski, Nick D
Brinkworth, Amanda J
Carabeo, Rey
author_facet Pokorzynski, Nick D
Brinkworth, Amanda J
Carabeo, Rey
author_sort Pokorzynski, Nick D
collection PubMed
description During infection, pathogens are starved of essential nutrients such as iron and tryptophan by host immune effectors. Without conserved global stress response regulators, how the obligate intracellular bacterium Chlamydia trachomatis arrives at a physiologically similar ‘persistent’ state in response to starvation of either nutrient remains unclear. Here, we report on the iron-dependent regulation of the trpRBA tryptophan salvage pathway in C. trachomatis. Iron starvation specifically induces trpBA expression from a novel promoter element within an intergenic region flanked by trpR and trpB. YtgR, the only known iron-dependent regulator in Chlamydia, can bind to the trpRBA intergenic region upstream of the alternative trpBA promoter to repress transcription. Simultaneously, YtgR binding promotes the termination of transcripts from the primary promoter upstream of trpR. This is the first description of an iron-dependent mechanism regulating prokaryotic tryptophan biosynthesis that may indicate the existence of novel approaches to gene regulation and stress response in Chlamydia.
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spelling pubmed-65042342019-05-09 A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis Pokorzynski, Nick D Brinkworth, Amanda J Carabeo, Rey eLife Chromosomes and Gene Expression During infection, pathogens are starved of essential nutrients such as iron and tryptophan by host immune effectors. Without conserved global stress response regulators, how the obligate intracellular bacterium Chlamydia trachomatis arrives at a physiologically similar ‘persistent’ state in response to starvation of either nutrient remains unclear. Here, we report on the iron-dependent regulation of the trpRBA tryptophan salvage pathway in C. trachomatis. Iron starvation specifically induces trpBA expression from a novel promoter element within an intergenic region flanked by trpR and trpB. YtgR, the only known iron-dependent regulator in Chlamydia, can bind to the trpRBA intergenic region upstream of the alternative trpBA promoter to repress transcription. Simultaneously, YtgR binding promotes the termination of transcripts from the primary promoter upstream of trpR. This is the first description of an iron-dependent mechanism regulating prokaryotic tryptophan biosynthesis that may indicate the existence of novel approaches to gene regulation and stress response in Chlamydia. eLife Sciences Publications, Ltd 2019-04-02 /pmc/articles/PMC6504234/ /pubmed/30938288 http://dx.doi.org/10.7554/eLife.42295 Text en © 2019, Pokorzynski 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
Pokorzynski, Nick D
Brinkworth, Amanda J
Carabeo, Rey
A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis
title A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis
title_full A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis
title_fullStr A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis
title_full_unstemmed A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis
title_short A bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in Chlamydia trachomatis
title_sort bipartite iron-dependent transcriptional regulation of the tryptophan salvage pathway in chlamydia trachomatis
topic Chromosomes and Gene Expression
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6504234/
https://www.ncbi.nlm.nih.gov/pubmed/30938288
http://dx.doi.org/10.7554/eLife.42295
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