In a previous study, we presented the dimer structure of DNA gyrase B' domain (GyrB C-terminal domain) from Mycobacterium tuberculosis and proposed a 'sluice-like' model for T-segment transport. However, the role of the dimer structure is still not well understood. Cross-linking and analytical ultracentrifugation experiments showed that the dimer structure exists both in the B' protein and in the full-length GyrB in solution. The cross-linked dimer of GyrB bound GyrA very weakly, but bound dsDNA with a much higher affinity than that of the monomer state. Using cross-linking and far-western analyses, the dimer state of GyrB was found to be involved in the ternary GyrA-GyrB-DNA complex. The results of mutational studies reveal that the dimer structure represents a state before DNA cleavage. Additionally, these results suggest that the dimer might also be present between the cleavage and reunion steps during processive transport.
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http://dx.doi.org/10.1093/nar/gkr553 | DOI Listing |
Viruses
January 2025
Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
Retroviral genome selection and virion assembly remain promising targets for novel therapeutic intervention. Recent studies have demonstrated that the Gag proteins of Rous sarcoma virus (RSV) and human immunodeficiency virus type-1 (HIV-1) undergo nuclear trafficking, colocalize with nascent genomic viral RNA (gRNA) at transcription sites, may interact with host transcription factors, and display biophysical properties characteristic of biomolecular condensates. In the present work, we utilized a controlled in vitro condensate assay and advanced imaging approaches to investigate the effects of interactions between RSV Gag condensates and viral and nonviral RNAs on condensate abundance and organization.
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January 2025
Department of Organic Chemistry and Technology, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3., 1111 Budapest, Hungary.
A series of α-hydroxy-alkylphosphonates and α-hydroxy-alkylphosphine oxides were synthesized by the Pudovik reaction of acetaldehyde and acetone with dialkyl phosphites or diarylphosphine oxides. The additions were performed in three different ways: in liquid phase using triethylamine as the catalyst (1), on the surface of AlO/KF solid catalyst (2), or by a MW-assisted NaCO-catalyzed procedure (3). In most of the cases, our methods were more efficient and more robust than those applied in the literature.
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January 2025
Cancer Microenvironment Branch, Division of Cancer Biology, Research Institute, National Cancer Center, Goyang-si 10408, Republic of Korea.
As a scaffolding protein, Raf kinase binding protein (RKIP) is involved in a variety of cellular pathways, including the Raf-MEK-ERK-cascade. It acts as a negative regulator by binding to its partners, making it an attractive target in the development of therapeutic strategies for cancer. Despite its structural stability as a monomer, RKIP may form a dimer, resulting in the switching of binding partners.
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January 2025
Instituto Andaluz de Ciencias de la Tierra (IACT-CSIC), Consejo Superior de Investigaciones Científicas, Av. de las Palmeras 4, 18100 Armilla, Granada, Spain.
Many properties of 2,4-dichlorophenoxyacetic acid (2,4-D) depend on its molecular environment, such as whether it is an isolated molecule, a dimer, or in a crystalline state. The molecular geometry, conformational analysis, and vibrational spectrum of 2,4-D were theoretically calculated using Density Functional Theory (DFT) methods. A new slightly more stable conformer was found, which is different to those previously reported.
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January 2025
N. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prosp. 31, 119991 Moscow, Russia.
The interaction of sodium phytate hydrate CHOP·xNa·yHO (phytNa) with Cu(OAc)·HO and 1,10-phenanthroline (phen) led to the anionic tetranuclear complex [Cu(HO)(phen)(phyt)]·2Na·2NH·32HO (), the structure of the latter was determined by X-ray diffraction analysis. The phytate is completely deprotonated; six phosphate fragments (with atoms P1-P6) are characterized by different spatial arrangements relative to the cyclohexane ring (1a5e conformation), which determines two different types of coordination to the complexing agents-P1 and P3, P4, and P6 have monodentate, while P2 and P5 are bidentately bound to Cu cations. The molecular structure of the anion complex is stabilized by a set of strong intramolecular hydrogen bonds involving coordinated water molecules.
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