We determined a 1.95 A X-ray crystal structure of a C-terminally truncated Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (CYT-18 protein) that functions in splicing group I introns. CYT-18's nucleotide binding fold and intermediate alpha-helical domains superimpose on those of bacterial TyrRSs, except for an N-terminal extension and two small insertions not found in nonsplicing bacterial enzymes. These additions surround the cyt-18-1 mutation site and are sites of suppressor mutations that restore splicing, but not synthetase activity. Highly constrained models based on directed hydroxyl radical cleavage assays show that the group I intron binds at a site formed in part by the three additions on the nucleotide binding fold surface opposite that which binds tRNATyr. Our results show how essential proteins can progressively evolve new functions.
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http://dx.doi.org/10.1016/j.molcel.2004.12.026 | DOI Listing |
Molecules
December 2024
Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, 90128 Palermo, Italy.
Molecular hybridization, which consists of the combination of two or more pharmacophores into a single molecule, is an innovative approach in drug design to afford new chemical entities with enhanced biological activity. In the present study, this strategy was pursued to develop a new series of 6,7-dimethoxy-4-piperazinylquinoline-3-carbonitrile derivatives (-) with potential antibiotic activity by combining the quinoline, the piperazinyl, and the benzoylamino moieties, three recurrent frameworks in antimicrobial research. Initial in silico evaluations were conducted on the designed compounds, highlighting favorable ADMET and drug-likeness properties, which were synthesized through a multistep strategy, isolated, and fully characterized.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
College of Food Science and Engineering, Qingdao Agricultural University, Qingdao 266109, Shandong, China; Bathurst Future Agri-Tech Institute, Qingdao Agricultural University, Qingdao, 266109, Shandong, China. Electronic address:
The growth and reproduction of microorganisms are dependent on nutrient supply. Here, Milk and LB media were utilized as nutrition sources for Escherichia coli, and the changes in bacterial and secretory proteins at 3 time points (3, 9, and 18 h) in the growth cycle were studied using a label-free proteomics technique. The findings revealed that the abundances of bacterial intracellular proteins inosine/xanthosine triphosphatase and universal stress protein F increase dramatically during the growth phase in milk and LB media.
View Article and Find Full Text PDFPharmaceuticals (Basel)
December 2024
Department of Biology, College of Science, Qassim University, Buraydah 51452, Saudi Arabia.
In Saudi Arabia, numerous plant species with promising medicinal properties are cultivated, widely traded, and commonly utilized in traditional medicine, including fenugreek (). This study aimed to comprehensively assess the phytochemical composition and antimicrobial potential of the Saudi cultivar of fenugreek using an integrative approach combining in vitro and in silico methodologies. A comprehensive investigation was conducted on the ethanol extract of fenugreek seeds, assessing its antibacterial, antifungal, properties.
View Article and Find Full Text PDFFEBS J
January 2025
Université d'Angers, Inserm, CNRS, CRCI2NA, ICO, Angers, France.
Senescence is a tumor suppressor mechanism triggered by oncogene expression and chemotherapy treatment. It orchestrates a definitive cessation of cell proliferation through the activation of the p53-p21 and p16-Rb pathways, coupled with the compaction of proliferative genes within heterochromatin regions. Some cancer cells have the ability to elude this proliferative arrest but the signaling pathways involved in circumventing senescence remain to be characterized.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, USA. Electronic address:
Human genetic disorders are often caused by mutations of compound heterozygosity, where each allele of the mutant gene harbors a different genetic lesion. However, studies of such mutations are hampered due to the lack of an appropriate model. Here we describe a kinetic model of compound heterozygous variants in an obligate enzyme dimer that contains one mutation in one monomer and the other mutation in the second monomer.
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