Flagellin is a bacterial protein that polymerizes into the flagellar filament and is essential for bacterial motility. When flagellated bacteria invade the host, flagellin is recognized by Toll-like receptor 5 (TLR5) as a pathogen invasion signal and eventually evokes the innate immune response. Here, we provide a conserved structural mechanism by which flagellins from Gram-negative γ-proteobacteria and Gram-positive Firmicutes bacteria bind and activate TLR5. The comparative structural analysis using our crystal structure of a complex between Bacillus subtilis flagellin (bsflagellin) and TLR5 at 2.1 Å resolution, combined with the alanine scanning analysis of the binding interface, reveals a common hot spot in flagellin for TLR5 activation. An arginine residue (bsflagellin R89) of the flagellin D1 domain and its adjacent residues (bsflagellin E114 and L93) constitute a hot spot that provides shape and chemical complementarity to a cavity generated by the loop of leucine-rich repeat 9 in TLR5. In addition to the flagellin D1 domain, the D0 domain also contributes to TLR5 activity through structurally dispersed regions, but not a single focal area. These results establish the groundwork for the future design of flagellin-based therapeutics.
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http://dx.doi.org/10.1038/srep40878 | DOI Listing |
Adv Radiat Oncol
February 2025
Department of Advanced Radiation Oncology and Proton Therapy, Inova Schar Cancer Institute, Fairfax, Virginia.
Purpose: This study evaluates the hypothesis that a volumetric skin-sparing planning technique (SSPT) will reduce acute dermatitis in patients treated to the breast or chest wall (CW) with proton pencil-beam scanning (PBS).
Methods And Materials: In January 2022, our center incorporated volumetric-based skin-sparing objectives in addition to skin hot spot evaluation as an SSPT. The SSPT incorporated an objective to limit the volume of a skin evaluation structure (skin-eval) receiving 95% of the prescription dose or more (V95%Rx) to ideally < 50%.
J Environ Manage
January 2025
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; Research Center of Environmental Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China. Electronic address:
Microplastics (MPs) are ubiquitous in aquatic environments, threatening the security of aquatic organisms. Identifying the emission node and hot spot of MPs holds significant importance in the pollution control of MPs. Wastewater is widely recognized as sink and source of MPs, while the direct evidence is insufficient.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, P.R. China.
Astaxanthin is a kind of carotenoid with a strong antioxidant ability, which has shown broad applications in the areas of healthcare, medicine, cosmetics, food additives, and aquaculture. With the increasing demand for natural products, the microbial production of astaxanthin has become a new hot spot. In this study, the astaxanthin synthesis pathway was first metabolically constructed in ()().
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
State Key Laboratory of Analytical Chemistry for Life Science, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
The birth and development of supramolecular chemistry have heralded a new era, where macrocycles have become an irreplaceable research tool. Therefore, the construction of novel macrocycles has become a hot spot. Tröger's base (TB), as a fragment with both rigidity and chirality, promises tremendous potential in the realm of supramolecular chemistry, and its unique properties continue to motivate researchers to explore its inclusion in macrocycles.
View Article and Find Full Text PDFSci Total Environ
January 2025
Department of Forest Biodiversity, Faculty of Forestry, University of Agriculture, al. 29 Listopada 46, 31-425 Kraków, Poland. Electronic address:
Tree-related Microhabitats (TreMs) are essential for sustaining forest biodiversity. Although TreMs represent ephemeral resources that are spread across the landscape, their spatial distribution within temperate forests remains poorly understood. To address this knowledge gap, we conducted a study on 90 sample plots (0.
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