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Title: Molecular control of gene expression by Brucella BaaR, an IclR-type transcriptional repressor

Abstract

The general stress response sigma factor σ E1 directly and indirectly regulates the transcription of dozens of genes that influence stress survival and host infection in the zoonotic pathogen Brucella abortus. Characterizing the functions of σ E1-regulated genes therefore would contribute to our understanding of B. abortus physiology and infection biology. σ E1 indirectly activates transcription of the IclR family regulator Bab2_0215, but the function of this regulator remains undefined. Here, we present a structural and functional characterization of Bab2_0215, which we have named Brucella adipic acid-activated regulator (BaaR). We found that BaaR adopts a classic IclR-family fold and directly represses the transcription of two operons with predicted roles in carboxylic acid oxidation. BaaR binds two sites on chromosome II between baaR and a divergently transcribed hydratase/dehydrogenase (acaD2), and it represses transcription of both genes. We identified three carboxylic acids (adipic acid, tetradecanedioic acid, and E-aminocaproic acid) and a lactone (E-caprolactone) that enhance transcription from the baaR and acaD2 promoters. However, neither the activating acids nor caprolactone enhanced transcription by binding directly to BaaR. Induction of baaR transcription by adipic acid required the gene bab2_0213, which encodes a major facilitator superfamily transporter, suggesting that Bab2_0213 transports adipic acid across themore » inner membrane. Finally, we conclude that a suite of structurally related organic molecules activate transcription of genes repressed by BaaR. Our study provides molecular-level understanding of a gene expression program in B. abortus that is downstream of σ E1.« less

Authors:
 [1];  [1];  [2];  [1];  [3];  [3];  [3];  [4]
  1. Univ. of Chicago, IL (United States). Dept. of Biochemistry and Molecular Biology; Univ. of Chicago, IL (United States). Howard Taylor Ricketts Lab.
  2. Univ. of Chicago, IL (United States). Howard Taylor Ricketts Lab.
  3. Argonne National Lab. (ANL), Argonne, IL (United States)
  4. Univ. of Chicago, IL (United States). Dept. of Biochemistry and Molecular Biology; Univ. of Chicago, IL (United States). Howard Taylor Ricketts Lab.; Univ. of Chicago, IL (United States). Dept. of Microbiology
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
National Institutes of Health (NIH). National Institute of Allergy and Infectious Diseases (NIAID); USDOE
OSTI Identifier:
1466337
Grant/Contract Number:  
AC02-06CH11357; U19AI107792; R01AI107159
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Biological Chemistry
Additional Journal Information:
Journal Volume: 293; Journal Issue: 19; Journal ID: ISSN 0021-9258
Publisher:
American Society for Biochemistry and Molecular Biology
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; Brucella abortus; IclR; RpoE1; adipic acid; sigma factor; stress response; tetradecanedioic acid; transcriptional regulation; β-oxidation; ε-aminocaproic acid; ε-caprolactone

Citation Formats

Herrou, Julien, Czyż, Daniel M., Fiebig, Aretha, Willett, Jonathan W., Kim, Youngchang, Wu, Ruiying, Babnigg, Gyorgy, and Crosson, Sean. Molecular control of gene expression by Brucella BaaR, an IclR-type transcriptional repressor. United States: N. p., 2018. Web. doi:10.1074/jbc.RA118.002045.
Herrou, Julien, Czyż, Daniel M., Fiebig, Aretha, Willett, Jonathan W., Kim, Youngchang, Wu, Ruiying, Babnigg, Gyorgy, & Crosson, Sean. Molecular control of gene expression by Brucella BaaR, an IclR-type transcriptional repressor. United States. doi:10.1074/jbc.RA118.002045.
Herrou, Julien, Czyż, Daniel M., Fiebig, Aretha, Willett, Jonathan W., Kim, Youngchang, Wu, Ruiying, Babnigg, Gyorgy, and Crosson, Sean. Thu . "Molecular control of gene expression by Brucella BaaR, an IclR-type transcriptional repressor". United States. doi:10.1074/jbc.RA118.002045. https://www.osti.gov/servlets/purl/1466337.
@article{osti_1466337,
title = {Molecular control of gene expression by Brucella BaaR, an IclR-type transcriptional repressor},
author = {Herrou, Julien and Czyż, Daniel M. and Fiebig, Aretha and Willett, Jonathan W. and Kim, Youngchang and Wu, Ruiying and Babnigg, Gyorgy and Crosson, Sean},
abstractNote = {The general stress response sigma factor σE1 directly and indirectly regulates the transcription of dozens of genes that influence stress survival and host infection in the zoonotic pathogen Brucella abortus. Characterizing the functions of σE1-regulated genes therefore would contribute to our understanding of B. abortus physiology and infection biology. σE1 indirectly activates transcription of the IclR family regulator Bab2_0215, but the function of this regulator remains undefined. Here, we present a structural and functional characterization of Bab2_0215, which we have named Brucella adipic acid-activated regulator (BaaR). We found that BaaR adopts a classic IclR-family fold and directly represses the transcription of two operons with predicted roles in carboxylic acid oxidation. BaaR binds two sites on chromosome II between baaR and a divergently transcribed hydratase/dehydrogenase (acaD2), and it represses transcription of both genes. We identified three carboxylic acids (adipic acid, tetradecanedioic acid, and E-aminocaproic acid) and a lactone (E-caprolactone) that enhance transcription from the baaR and acaD2 promoters. However, neither the activating acids nor caprolactone enhanced transcription by binding directly to BaaR. Induction of baaR transcription by adipic acid required the gene bab2_0213, which encodes a major facilitator superfamily transporter, suggesting that Bab2_0213 transports adipic acid across the inner membrane. Finally, we conclude that a suite of structurally related organic molecules activate transcription of genes repressed by BaaR. Our study provides molecular-level understanding of a gene expression program in B. abortus that is downstream of σE1.},
doi = {10.1074/jbc.RA118.002045},
journal = {Journal of Biological Chemistry},
number = 19,
volume = 293,
place = {United States},
year = {2018},
month = {3}
}

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