scholarly journals Characterization of opposing responses to phenol by Bacillus subtilis chemoreceptors

2022 ◽  
Author(s):  
Girija A. Bodhankar ◽  
Payman Tohidifar ◽  
Zachary L. Foust ◽  
George W. Ordal ◽  
Christopher V. Rao
Keyword(s):  
Bacillus Subtilis ◽  
Soil Microbes ◽  
Bacterial Chemotaxis ◽  
Environmental Cues ◽  
Saturation Transfer ◽  
Signaling Domain ◽  
Direct Binding ◽  
Related Compounds

Bacillus subtilis employs ten chemoreceptors to move in response to chemicals in its environment. While the sensing mechanisms have been determined for many attractants, little is known about the sensing mechanisms for repellents. In this work, we investigated phenol chemotaxis in B. subtilis . Phenol is an attractant at low, micromolar concentrations, and a repellent at high, millimolar concentrations. McpA was found to be the principal chemoreceptor governing the repellent response to phenol and other related aromatic compounds. In addition, the chemoreceptors McpC and HemAT were found to govern the attractant response to phenol and related compounds. Using chemoreceptor chimeras, McpA was found to sense phenol using its signaling domain rather than its sensing domain. These observations were substantiated in vitro, where direct binding of phenol to the signaling domain of McpA was observed using saturation-transfer difference nuclear magnetic resonance. These results further advance our understanding of B. subtilis chemotaxis and further demonstrate that the signaling domain of B. subtilis chemoreceptors can directly sense chemoeffectors. IMPORTANCE Bacterial chemotaxis is commonly thought to employ a sensing mechanism involving the extracellular sensing domain of chemoreceptors. Some ligands, however, appear to be sensed by the signaling domain. Phenolic compounds, commonly found in soil and root exudates, provide environmental cues for soil microbes like Bacillus subtilis . We show that phenol is sensed both as an attractant and a repellent. While the mechanism for sensing phenol as an attractant is still unknown, we found that phenol is sensed as a repellent by the signaling domain of the chemoreceptor McpA. This study furthers our understanding of the unconventional sensing mechanisms employed by the B. subtilis chemotaxis pathway.

scholarly journals Characterization of opposing responses to phenol by Bacillus subtilis chemoreceptors

2021 ◽  
Author(s):  
Girija A. Bodhankar ◽  
Payman Tohidifar ◽  
Zachary L. Foust ◽  
George W. Ordal ◽  
Christopher V. Rao
Keyword(s):  
Bacillus Subtilis ◽  
Soil Microbes ◽  
Bacterial Chemotaxis ◽  
Environmental Cues ◽  
Saturation Transfer ◽  
Signaling Domain ◽  
Direct Binding ◽  
Related Compounds

ABSTRACTBacillus subtilis employs ten chemoreceptors to move in response to chemicals in its environment. While the sensing mechanisms have been determined for many attractants, little is known about the sensing mechanisms for repellents. In this work, we investigated phenol chemotaxis in B. subtilis. Phenol is an attractant at low, micromolar concentrations, and a repellent at high, millimolar concentrations. McpA was found to be the principal chemoreceptor governing the repellent response to phenol and other related aromatic compounds. In addition, the chemoreceptors McpC and HemAT were found to the govern the attractant response to phenol and related compounds. Using receptor chimeras, McpA was found to sense phenol using its signaling domain rather than its sensing domain. These observations were substantiated in vitro, where direct binding of phenol to the signaling domain of McpA was observed using saturation-transfer difference nuclear magnetic resonance. These results further advance our understanding of B. subtilis chemotaxis and demonstrate that the signaling domain of B. subtilis chemoreceptors can directly sense chemoeffectors.IMPORTANCEBacterial chemotaxis is commonly thought to employ a sensing mechanism involving the extracellular sensing domain of chemoreceptors. Some ligands, however, appear to be sensed by the signaling domain. Phenolic compounds, commonly found in soil and root exudates, provide environmental cues for soil microbes like Bacillus subtilis. We show that phenol is sensed both as an attractant and a repellent. While mechanism for sensing phenol as an attractant is still unknown, we found that phenol is sensed as a repellent by the signaling domain of the chemoreceptor McpA. This study furthers our understanding of the unconventional sensing mechanisms employed by the B. subtilis chemotaxis pathway.

In vitro characterization of N-terminal truncated EpsC from Bacillus subtilis 168, a UDP-N-acetylglucosamine 4,6-dehydratase

2018 ◽  
Vol 657 ◽  
pp. 78-88 ◽  
Author(s):  
Chinmayi R. Kaundinya ◽  
Handanahal S. Savithri ◽  
K. Krishnamurthy Rao ◽  
Petety V. Balaji
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Subtilis 168 ◽  
In Vitro Characterization

scholarly journals σIfromBacillus subtilis: Impact on Gene Expression and Characterization of σI-Dependent Transcription That Requires New Types of Promoters with Extended −35 and −10 Elements

2018 ◽  
Vol 200 (17) ◽  
Author(s):  
Olga Ramaniuk ◽  
Martin Převorovský ◽  
Jiří Pospíšil ◽  
Dragana Vítovská ◽  
Olga Kofroňová ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Iron Metabolism ◽  
Transcription Initiation ◽  
Iron Homeostasis ◽  
Model Organism ◽  
Content Type ◽  
Σ Factor

ABSTRACTThe σIsigma factor fromBacillus subtilisis a σ factor associated with RNA polymerase (RNAP) that was previously implicated in adaptation of the cell to elevated temperature. Here, we provide a comprehensive characterization of this transcriptional regulator. By transcriptome sequencing (RNA-seq) of wild-type (wt) and σI-null strains at 37°C and 52°C, we identified ∼130 genes affected by the absence of σI. Further analysis revealed that the majority of these genes were affected indirectly by σI. The σIregulon, i.e., the genes directly regulated by σI, consists of 16 genes, of which eight (thedhbandykuoperons) are involved in iron metabolism. The involvement of σIin iron metabolism was confirmed phenotypically. Next, we set up anin vitrotranscription system and defined and experimentally validated the promoter sequence logo that, in addition to −35 and −10 regions, also contains extended −35 and −10 motifs. Thus, σI-dependent promoters are relatively information rich in comparison with most other promoters. In summary, this study supplies information about the least-explored σ factor from the industrially important model organismB. subtilis.IMPORTANCEIn bacteria, σ factors are essential for transcription initiation. Knowledge about their regulons (i.e., genes transcribed from promoters dependent on these σ factors) is the key for understanding how bacteria cope with the changing environment and could be instrumental for biotechnologically motivated rewiring of gene expression. Here, we characterize the σIregulon from the industrially important model Gram-positive bacteriumBacillus subtilis. We reveal that σIaffects expression of ∼130 genes, of which 16 are directly regulated by σI, including genes encoding proteins involved in iron homeostasis. Detailed analysis of promoter elements then identifies unique sequences important for σI-dependent transcription. This study thus provides a comprehensive view on this underexplored component of theB. subtilistranscription machinery.

scholarly journals Biochemical Characterization of the C4-Dicarboxylate Transporter DctA from Bacillus subtilis

2010 ◽  
Vol 192 (11) ◽  
pp. 2900-2907 ◽  
Author(s):  
Maarten Groeneveld ◽  
Ruud G. J. Detert Oude Weme ◽  
Ria H. Duurkens ◽  
Dirk Jan Slotboom
Keyword(s):  
Bacillus Subtilis ◽  
Biochemical Characterization ◽  
Krebs Cycle ◽  
Membrane Vesicles ◽  
Positive Bacterium ◽  
Proton Symport ◽  
Negative Membrane Potential ◽  
Isolated Membrane Vesicles

ABSTRACT Bacterial secondary transporters of the DctA family mediate ion-coupled uptake of C4-dicarboxylates. Here, we have expressed the DctA homologue from Bacillus subtilis in the Gram-positive bacterium Lactococcus lactis. Transport of dicarboxylates in vitro in isolated membrane vesicles was assayed. We determined the substrate specificity, the type of cotransported ions, the electrogenic nature of transport, and the pH and temperature dependence patterns. DctA was found to catalyze proton-coupled symport of the four C4-dicarboxylates from the Krebs cycle (succinate, fumurate, malate, and oxaloacetate) but not of other mono- and dicarboxylates. Because (i) succinate-proton symport was electrogenic (stimulated by an internal negative membrane potential) and (ii) the divalent anionic form of succinate was recognized by DctA, at least three protons must be cotransported with succinate. The results were interpreted in the light of the crystal structure of the homologous aspartate transporter GltPh from Pyrococcus horikoshii.

scholarly journals Characterization of the Bacillus subtilis GTPase YloQ and its role in ribosome function

2005 ◽  
Vol 389 (3) ◽  
pp. 843-852 ◽  
Author(s):  
Tracey L. Campbell ◽  
Denis M. Daigle ◽  
Eric D. Brown
Keyword(s):  
Bacillus Subtilis ◽  
Cellular Phenotype ◽  
Ribosomal Subunits ◽  
E Coli ◽  
Chemical Genetic ◽  
Small Molecule Probes ◽  
Conditional Mutant ◽  
Peptidyl Transferase Centre

We present an analysis of the cellular phenotype and biochemical activity of a conserved bacterial GTPase of unknown function (YloQ and YjeQ in Bacillus subtilis and Escherichia coli respectively) using a collection of antibiotics of diverse mechanisms and chemical classes. We created a yloQ deletion strain, which exhibited a slow growth phenotype and formed chains of filamentous cells. Additionally, we constructed a conditional mutant in yloQ, where growth was dependent on inducible expression from a complementing copy of the gene. In phenotypic studies, depletion of yloQ sensitized cells to antibiotics that bind at the peptide channel or peptidyl transferase centre, providing the first chemical genetic evidence linking this GTPase to ribosome function. Additional experiments using these small-molecule probes in vitro revealed that aminoglycoside antibiotics severely affected a previously characterized ribosome-associated GTPase activity of purified, recombinant YjeQ from E. coli. None of the antibiotics tested competed with YjeQ for binding to 30 or 70 S ribosomes. A closer examination of YloQ depletion revealed that the polyribosome profiles were altered and that decreased expression of YloQ led to the accumulation of ribosomal subunits at the expense of intact 70 S ribosomes. The present study provides the first evidence showing that YloQ/YjeQ may be involved in several areas of cellular metabolism, including cell division and ribosome function.

scholarly journals Structural characterization of the late competence protein ComFB from Bacillus subtilis

2015 ◽  
Vol 35 (2) ◽  
Author(s):  
Tatyana A. Sysoeva ◽  
Lukas B. Bane ◽  
Daphne Y. Xiao ◽  
Baundauna Bose ◽  
Scott S. Chilton ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Structural Characterization ◽  
Competence Development ◽  
Regulatory Role ◽  
In Vivo Studies ◽  
Genetic Competence

Development of genetic competence in Bacillus subtilis results in expression of late competence genes, including comFB. In vitro and in vivo studies revealed that ComFB dimerizes, binds zinc, and possibly plays a regulatory role in competence development.

Sign in / Sign up

Export Citation Format

Share Document