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Anti-CRISPR (Acr) proteins are natural inhibitors of CRISPR-Cas systems, found in bacteriophages and other genetic elements. AcrIE3, identified in a Pseudomonas phage, inactivates the type I-E CRISPR-Cas system in Pseudomonas aeruginosa by engaging with the Cascade complex. However, its precise inhibition mechanism has remained elusive. In this study, we present a comprehensive structural and biochemical analysis of AcrIE3, providing mechanistic insight into its anti-CRISPR function. Our results reveal that AcrIE3 selectively binds to the Cas8e subunit of the Cascade complex. The crystal structure of AcrIE3 exhibits an all-helical fold with a negatively charged surface. Through extensive mutational analyses, we show that AcrIE3 interacts with the protospacer adjacent motif (PAM) recognition site in Cas8e through its negatively charged surface residues. These findings enhance our understanding of the structure and function of type I-E Acr proteins, suggesting PAM interaction sites as primary targets for divergent Acr inhibitors.
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http://dx.doi.org/10.1016/j.str.2024.10.024 | DOI Listing |
J Med Chem
September 2025
State Key Laboratory of Bioactive Molecules and Druggability Assessment, Guangdong Basic Research Center of Excellence for Natural Bioactive Molecules and Discovery of Innovative Drugs, International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Discovery o
Aberrant activation of fibroblast growth factor receptors (FGFRs) plays a critical role in tumorigenesis across multiple cancer types, driving the development of various FGFR inhibitors. Despite clinical advances, therapeutic efficacy remains limited by the emergence of drug resistance, primarily mediated by gatekeeper mutations in FGFRs. To overcome this challenge, we designed and synthesized a novel series of 7-(1-methyl-1-indole-3-yl)-5-pyrrolo[2,3-]pyrazine derivatives as covalent pan-FGFR inhibitors targeting both wild-type and gatekeeper mutants.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
Department of Materials Science and Engineering, College of Engineering, Texas A&M University, College Station, Texas 77843, United States.
Hydrogel-based bioinks are widely adopted in digital light processing (DLP) 3D printing. Modulating their mechanical properties is especially beneficial in biomedical applications, such as directing cell activity toward tissue regeneration and healing. However, in both monolithic and granular hydrogels, the tunability of mechanical properties is limited to parameters such as cross-linking or packing density.
View Article and Find Full Text PDFPLoS Genet
September 2025
Dept of Biology, Portland State University, Portland, Oregon, United States of America.
The ability to complete DNA replication as replisomes converge has recently been shown to be a highly-regulated, multi-enzymatic process. Converging forks also are likely to generate unique supercoiled, tangled, or knotted substrates. These structures are typically resolved by one of the four topoisomerases encoded by Escherichia coli.
View Article and Find Full Text PDFJ Labelled Comp Radiopharm
September 2025
National Key Laboratory for the Development and Utilization of Forest Food Resources, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, Jiangsu, China.
Carbon-11 (C)-labeled radiotracers are invaluable tools in positron emission tomography (PET), enabling real-time visualization of biochemical processes with high sensitivity and specificity. Among the various C synthons, cyclotron-produced [C]CO is a fundamental precursor, though its direct incorporation into complex molecules has traditionally been limited by its low reactivity, gaseous form, and short half-life. Recent advances in [C]CO fixation chemistry through both nonphotocatalytic and photocatalytic methods have significantly expanded its utility in the synthesis of structurally diverse compounds, including carboxylic acids, carbonates, carbamates, amides, and ureas.
View Article and Find Full Text PDFDrug Dev Res
September 2025
Department of Pharmaceutics, School of Pharmacy, Center for Nano Drug/Gene Delivery and Tissue Engineering, Jiangsu Provincial Research Center for Medicinal Function Development of New Food Resources, Jiangsu University, Zhenjiang, Jiangsu, China.
Liver cancer is the fourth most deadly cancer worldwide, but existing treatment options are insufficient, thus highlighting the urgent need for new therapeutic agents. Taxanes, known for their anticancer properties, provide a promising avenue for intervention. In this study, a tetracyclic taxane compound with antitumor activity (taxinine) was extracted and isolated from Taxus chinensis (T.
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