Stringent factors orchestrate bacterial cell reprogramming through increasing the level of the alarmones (p)ppGpp. In Beta- and Gammaproteobacteria, SpoT hydrolyzes (p)ppGpp to counteract the synthetase activity of RelA. However, structural information about how SpoT controls the levels of (p)ppGpp is missing. Here we present the crystal structure of the hydrolase-only SpoT from Acinetobacter baumannii and uncover the mechanism of intramolecular regulation of 'long'-stringent factors. In contrast to ribosome-associated Rel/RelA that adopt an elongated structure, SpoT assumes a compact τ-shaped structure in which the regulatory domains wrap around a Core subdomain that controls the conformational state of the enzyme. The Core is key to the specialization of long RelA-SpoT homologs toward either synthesis or hydrolysis: the short and structured Core of SpoT stabilizes the τ-state priming the hydrolase domain for (p)ppGpp hydrolysis, whereas the longer, more dynamic Core domain of RelA destabilizes the τ-state priming the monofunctional RelA for efficient (p)ppGpp synthesis.
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http://dx.doi.org/10.1038/s41589-022-01198-x | DOI Listing |
Biosensors (Basel)
November 2024
Institute of Laser Engineering, Osaka University, Suita 565-0871, Osaka, Japan.
Biosensors operating in the terahertz (THz) region are gaining substantial interest in biomedical analysis due to their significant potential for high-sensitivity trace-amount solution detection. However, progress in compact, high-sensitivity chips and methods for simple, rapid and trace-level measurements is limited by the spatial resolution of THz waves and their strong absorption in polar solvents. In this work, a compact nonlinear optical crystal (NLOC)-based reflective THz biosensor with a few arrays of asymmetrical meta-atoms was developed.
View Article and Find Full Text PDFDent J (Basel)
November 2024
Department of Dental Medicine, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania.
Unlabelled: White spot lesions (WSLs) are demineralized lesions of the enamel that form in the presence of bacterial plaque, affecting the aesthetics by modifying the refractive index of the enamel, giving the characteristic "chalky" aspect. They have various causes, including fixed orthodontic treatments, improper hygiene, fluorosis and genetic factors.
Background/objectives: Considering the latest need for dental aesthetics and the popularization of fixed orthodontic treatments, the need to effectively treat WSLs has increased.
Plant Dis
December 2024
Kansas State University, Plant Pathology, 4024 Throckmorton PSC, Manhattan, Kansas, United States, 66506.
Tan spot, caused by Pyrenophora tritici-repentis (Ptr) carries any of at least three identified necrotrophic effectors (NE) as part of its host invasion repertoire (Ptr ToxA, Ptr ToxB, and Ptr ToxC). The 8 possible combinations of these genes, or their absence, are described using a race system. These races characterize the disease phenotype observed on a wheat differential set.
View Article and Find Full Text PDFFront Public Health
December 2024
College of Health Sciences, Oda Bultum University, Chiro, Ethiopia.
Background: Although proper latrine utilization is one of the best ways to reduce the risk of infection, it remains a challenge in the majority of rural communities in developing countries such as Ethiopia. Studies have demonstrated the link between individual behavior and latrine use, but there is a paucity of evidence on individual risk perception, perceived social pressure norms, social identity, and perceived ability, which plays an indubitable role in health and behavior change, especially in rural communities.
Objective: This study aimed to identify contextual and psychosocial factors associated with latrine utilization among rural communities in Lomabosa district, Ethiopia.
Methods Mol Biol
December 2024
Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA, USA.
Mass spectrometry-based investigation of the heterogeneous glycoproteome from complex biological specimens is a robust approach to mapping the structure, function, and dynamics of the glycome and proteome. Sampling whole wet tissues often provides a large amount of starting material; however, there is a reasonable variability in tissue handling prior to downstream processing steps, and it is difficult to capture all the different biomolecules from a specific region. The on-slide tissue digestion approach, outlined in this protocol chapter, is a simple and cost-effective method that allows comprehensive mapping of the glycoproteome from a single spot of tissue of 1 mm or greater diameter.
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