sigma B is a secondary sigma factor of Bacillus subtilis. sigma B-dependent transcription is induced when B. subtilis enters the stationary phase of growth or is exposed to any of a number of different environmental stresses. Three genes (rsbV, rsbW, and rsbX), which are cotranscribed with the sigma B structural gene (sigB), encode regulators of sigma B-dependent gene expression. RsbW and RsbV have been shown to control sigma B activity, functioning as an inhibitory sigma B binding protein and its antagonist, respectively. Using the SPAC promoter (PSPAC) to control the expression of the sigB operon, a ctc::lacZ reporter system to monitor sigma B activity, and monoclonal antibodies to determine the levels of sigB operon products, we have now obtained evidence that RsbX is an indirect regulator of sigma B activity. Genetic data and in vivo measurements argue that RsbX negatively regulates an extension of the RsbV-RsbW pathway that requires the product of an additional regulatory gene (rsbU) which lies immediately upstream of the sigB operon. The results are consistent with RsbU, or a process dependent on RsbU, being able to facilitate the RsbV-dependent release of sigma B from RsbW but normally prevented from doing this by RsbX.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC176563 | PMC |
| http://dx.doi.org/10.1128/jb.177.1.114-122.1995 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A spiking neural network for active efficient coding.
Front Robot AI
January 2025
Life- and Neurosciences, Frankfurt Institute for Advanced Studies, Frankfurt am Main, Germany.
Biological vision systems simultaneously learn to efficiently encode their visual inputs and to control the movements of their eyes based on the visual input they sample. This autonomous joint learning of visual representations and actions has previously been modeled in the Active Efficient Coding (AEC) framework and implemented using traditional frame-based cameras. However, modern event-based cameras are inspired by the retina and offer advantages in terms of acquisition rate, dynamic range, and power consumption.
View Article and Find Full Text PDFAcute stress triggers sex-dependent rapid alterations in the human small intestine microbiota composition.
Front Microbiol
January 2025
Laboratory of Neuro-Immuno-Gastroenterology, Digestive System Research Unit, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain.
Background/aims: Digestive disorders of gut-brain interaction (DGBI) are very common, predominant in females, and usually associated with intestinal barrier dysfunction, dysbiosis, and stress. We previously found that females have increased susceptibility to intestinal barrier dysfunction in response to acute stress. However, whether this is associated with changes in the small bowel microbiota remains unknown.
View Article and Find Full Text PDFMechanistic and bibliometric insights into -mediated biofilm regulation and its strategic role in food safety applications.
Crit Rev Food Sci Nutr
January 2025
Food Safety and Regulatory Science, Chung-Ang University, Anseong-Si, Republic of Korea.
Biofilm, complex structures formed by microorganisms within an extracellular polymeric matrix, pose significant challenges in the sector by harboring dangerous pathogens and complicating decontamination, thereby increasing the risk of foodborne illnesses. This article provides a comprehensive review of the sigma factor, 's role in biofilm development, specifically in gram-negative bacteria, and how the genetic, environmental, and regulatory elements influence activity with its critical role in bacterial stress responses. Our findings reveal that is a pivotal regulator of biofilm formation, enhancing bacterial survival in adverse conditions.
View Article and Find Full Text PDFCompetitive Effect of Surface Hydrophobicity-Hydrophilicity and the Number of Accessible Protons on Water-Assisted Proton Conductivity in Metal-Organic Frameworks: Dielectric σ-Relaxation Triggered by Disordered Guest Ionic Migration and Its Mechanism.
Inorg Chem
January 2025
Beijing Spacecrafts Manufacturing Factory, Beijing 100094, P. R. China.
The rapid upsurge of metal-organic frameworks (MOFs) has sparked profound interest in their potential as proton conductors for proton exchange membrane fuel cells. However, proton-conducting behaviors of hydrophobic MOFs remain poorly understood compared with their hydrophilic counterparts, largely due to the absence of a microscopic phase separation structure akin to that found in Nafion membranes. Herein, we demonstrate a strategy for regulating the structures and proton conductivities of MOFs by separately incorporating hydrophobic -C(CF)- group alongside hydrophilic -O- and -SO- groups into organic ligands as linkers.
View Article and Find Full Text PDFComparison of Hydrogen Bonded Organic Framework with Reduced Graphene Oxide-Pd Based Nanocatalyst: Which One Is More Efficient for Entrapment of Nitrophenol Pollutants?
Langmuir
January 2025
Prof. Rashidi Laboratory of Organometallic Chemistry & Material Chemistry, Department of Chemistry, College of Science, Shiraz University, Shiraz, 7194684795, Iran.
In this study, a Pd nanoparticles@hydrogen-bonded organic framework (Pd NPs@HOF) thin film was fabricated at the toluene-water interface. The HOF was formed through the interaction of trimesic acid (TMA) and melamine (Mel) in the water phase, while Pd(0) was produced from the reduction of [PdCl(cod)] in the organic phase. The as-synthesized Pd NPs@HOF thin film was demonstrated to be an effective catalyst for the selective reduction of -nitrophenol and -nitrophenol to -aminophenol and -aminophenol.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!