A recombinant chimeric elongation factor containing the region of EF-1 alpha from Sulfolobus solfataricus harboring the site for GDP and GTP binding and GTP hydrolysis (SsG) and domains M and C of Escherichia coli EF-Tu (EcMC) was studied. SsG-EcMC did not sustain poly(Phe) synthesis in either S. solfataricus or E. coli assay system. This was probably due to the inability of the chimera to interact with aa-tRNA. The three-dimensional modeling of SsG-EcMC indicated only small structural differences compared to the Thermus aquaticus EF-Tu in the ternary complex with aa-tRNA and GppNHp, which did not account for the observed inability to interact with aa-tRNA. The addition of the nucleotide exchange factor SsEF-1 beta was not required for poly(Phe) synthesis since the chimera was already able to exchange [(3)H]GDP for GTP at very high rate even at 0 degrees C. Compared to that of SsEF-1 alpha, the affinity of the chimera for guanine nucleotides was increased and the k(cat) of the intrinsic GTPase was 2-fold higher. The heat stability of SsG-EcMC was 3 and 13 degrees C lower than that displayed by SsG and SsEF-1alpha, respectively, but 30 degrees C higher than that of EcEF-Tu. This pattern remained almost the same if the melting curves of the proteins being investigated were considered instead. The chimeric elongation factor was more thermophilic than SsG and SsEF-1 alpha up to 70 degrees C; at higher temperatures, inactivation occurred.
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http://dx.doi.org/10.1021/bi990418d | DOI Listing |
J Virol
January 2025
Department of Viroscience, Erasmus Medical Center, Rotterdam, the Netherlands.
Human metapneumovirus (HMPV) is an important causative agent of respiratory tract disease. Fundamental knowledge of the interaction between HMPV and the innate immune system could lead to the design of novel antiviral therapies. Previously, we demonstrated that HMPV M2-2 deletion mutants had hypermutated genomes and contained defective interfering particles (DIs), which are potent inducers of the IFN response.
View Article and Find Full Text PDFBiomaterials
December 2024
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China. Electronic address:
Epithelial-mesenchymal transition (EMT) is a key phenotypic switch in cancer metastasis, leading to fatal consequences for patients. Under geometric constraints, the morphology of cancer cells changes in both cellular and subcellular levels, whose effects on EMT are, however, not fully understood. Herein, we designed and fabricated chimeric micropatterns of polystyrene (PS) with adhesion contrast to reveal the impacts of cell shapes and nuclear shapes on EMT in a decoupled way.
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December 2024
MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China; Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, U.S. Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA. Electronic address:
With increasing regulations restricting antibiotic use in animal feed, the need for alternative strategies to prevent and manage necrotic enteritis (NE) has become imperative. As a result, developing effective vaccines has emerged as a top priority for broiler chicken health management. Coccidial infections are a well-established predisposing factor for NE, underscoring the importance of controlling coccidiosis to help mitigate NE outbreaks.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Department of Industrial Plant Science and Technology, Chungbuk National University, Cheongju 28644, Korea.
Plants have evolved photoreceptors to optimize their development during primary growth, including germination, hypocotyl elongation, cotyledon opening, and root growth, allowing them to adapt to challenging light conditions. The light signaling transduction pathway during seedling establishment has been extensively studied, but little molecular evidence is available for light-regulated secondary growth, and how light regulates cambium-derived tissue production remains largely unexplored. Here, we show that CRYPTOCHROME (CRY)-dependent blue light signaling and the subsequent attenuation of ELONGATED HYPOCOTYL 5 (HY5) movement to hypocotyls are key inducers of xylem fiber differentiation in Using grafted chimeric plants and hypocotyl-specific transcriptome sequencing of light signaling mutants under controlled light conditions, we demonstrate that the perception of blue light by CRYs in shoots drives secondary cell wall (SCW) deposition at xylem fiber cells during the secondary growth of hypocotyls.
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October 2024
Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Rogel Cancer Center, University of Michigan, Ann Arbor, MI 48109, USA; Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Urology, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address:
Cyclin-dependent kinases 12/13 play pivotal roles in orchestrating transcription elongation, DNA damage response, and maintenance of genomic stability. Biallelic CDK12 loss has been documented in various malignancies. Here, we develop a selective CDK12/13 PROTAC degrader, YJ9069, which effectively inhibits proliferation in subsets of prostate cancer cells preferentially over benign immortalized cells.
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