5WHM

Crystal Structure of IclR Family Transcriptional Regulator from Brucella abortus

Summary for 5WHM

• Entry DOI: 10.2210/pdb5whm/pdb
• Descriptor: IclR family transcriptional regulator, ACETIC ACID, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: helix-turn-helix, transcription factor, chicago center for functional annotation, midwest center for structural genomics, mcsg, psi-biology, transcription
• Biological source: Brucella abortus
• Total number of polymer chains: 4
• Total formula weight: 121179.01

Authors

Kim, Y.,Wu, R.,Tesar, C.,Endres, M.,Babnigg, G.,Crosson, S.,Joachimiak, A.,Midwest Center for Structural Genomics (MCSG) (deposition date: 2017-07-17, release date: 2017-08-23, Last modification date: 2024-11-06)

Primary citation

Herrou, J.,Czyz, D.M.,Fiebig, A.,Willett, J.W.,Kim, Y.,Wu, R.,Babnigg, G.,Crosson, S.
Molecular control of gene expression byBrucellaBaaR, an IclR-type transcriptional repressor.
J. Biol. Chem., 293:7437-7456, 2018

PubMed Abstract: The general stress response sigma factor σ directly and indirectly regulates the transcription of dozens of genes that influence stress survival and host infection in the zoonotic pathogen Characterizing the functions of σ-regulated genes therefore would contribute to our understanding of physiology and infection biology. σ 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 rucella dipic acid-ctivated egulator (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 and a divergently transcribed hydratase/dehydrogenase (), and it represses transcription of both genes. We identified three carboxylic acids (adipic acid, tetradecanedioic acid, and ϵ-aminocaproic acid) and a lactone (ϵ-caprolactone) that enhance transcription from the and promoters. However, neither the activating acids nor caprolactone enhanced transcription by binding directly to BaaR. Induction of transcription by adipic acid required the gene , which encodes a major facilitator superfamily transporter, suggesting that Bab2_0213 transports adipic acid across the inner membrane. 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 that is downstream of σ.

PubMed: 29567835
DOI: 10.1074/jbc.RA118.002045

Experimental method

X-RAY DIFFRACTION (1.95 Å)