MRE11-RAD50 is a key early response protein for processing DNA ends of broken chromosomes for repair, yet how RAD50 nucleotide dynamics regulate MRE11 nuclease activity is poorly understood. We report here that ATP binding and ATP hydrolysis cause a striking butterfly-like opening and closing of the RAD50 subunits, and each structural state has a dramatic functional effect on MRE11. RAD50-MRE11 has an extended conformation in solution when MRE11 is an active nuclease. However, ATP binding to RAD50 induces a closed conformation, and in this state MRE11 is an endonuclease. ATP hydrolysis opens the RAD50-MRE11 complex, and MRE11 maintains exonuclease activity. Thus, ATP hydrolysis is a molecular switch that converts MRE11 from an endonuclease to an exonuclease. We propose a testable model in which the open-closed transitions are used by RAD50-MRE11 to discriminate among DNA ends and drive the choice of recombination pathways.
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http://dx.doi.org/10.1074/jbc.M111.307041 | DOI Listing |
PLoS One
December 2024
College of Agriculture, Xinyang Agriculture and Forestry University, Xinyang, China.
The ATP-dependent zinc metalloprotease (FtsH) protein gene family is essential for plant growth, development, and stress responses. Although FtsH genes have been identified in various plant species, the FtsH gene family in wheat (Triticum aestivum) remains unstudied. In this study, we identified 11 TaFtsH genes with uneven chromosomal distribution, significant variations in gene sequence length, and differing intron numbers among individual members.
View Article and Find Full Text PDFSubcell Biochem
December 2024
Department of Macromolecular Structure, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain.
Viruses shield their genetic information by enclosing the viral nucleic acid inside a protein shell (capsid), in a process known as genome packaging. Viruses follow essentially two main strategies to package their genome: Either they co-assemble their genetic material together with the capsid protein or an empty shell (procapsid) is first assembled and then the genome is pumped inside the capsid by a molecular motor that uses the energy released by ATP hydrolysis. During packaging the viral nucleic acid is highly condensed through a meticulous arrangement in concentric layers inside the capsid.
View Article and Find Full Text PDFMetabolites
November 2024
Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS, University Lyon, F-69367 Lyon, France.
Phosphatases are enzymes that catalyze the hydrolysis of phosphate esters. They play critical roles in diverse biological processes such as extracellular nucleotide homeostasis, transport of molecules across membranes, intracellular signaling pathways, or vertebrate mineralization. Among them, tissue-nonspecific alkaline phosphatase (TNAP) is today increasingly studied, due to its ubiquitous expression and its ability to dephosphorylate a very broad range of substrates and participate in several different biological functions.
View Article and Find Full Text PDFNucleic Acids Res
December 2024
Department of Biochemistry, Indian Institute of Science, CV Raman Road, Bengaluru 560012, India.
Saccharomyces cerevisiae meiosis-specific Hop1, a structural constituent of the synaptonemal complex, also facilitates the formation of programmed DNA double-strand breaks and the pairing of homologous chromosomes. Here, we reveal a serendipitous discovery that Hop1 possesses robust DNA-independent ATPase activity, although it lacks recognizable sequence motifs required for ATP binding and hydrolysis. By leveraging molecular docking combined with molecular dynamics simulations and biochemical assays, we identified an ensemble of five amino acid residues in Hop1 that could potentially participate in ATP-binding and hydrolysis.
View Article and Find Full Text PDFEur J Pharmacol
December 2024
Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, 33302, Taiwan; Department of Obstetrics and Gynecology, Taipei Chang Gung Memorial Hospital, Taipei, 10507, Taiwan; Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan, 33302, Taiwan; Molecular Medicine Research Center, College of Medicine, Chang Gung University, Taoyuan, 33302, Taiwan. Electronic address:
Multidrug resistance (MDR) remains a significant obstacle in cancer treatment, primarily attributable to the overexpression of ATP-binding cassette (ABC) transporters such as ABCB1 and ABCG2 within cancer cells. These transporters actively diminish the effectiveness of cytotoxic drugs by facilitating ATP hydrolysis-dependent drug efflux, thereby reducing intracellular drug accumulation. Given the absence of approved treatments for multidrug-resistant cancers and the established benefits of combining tyrosine kinase inhibitors (TKIs) with conventional anticancer drugs, we investigate the potential of vodobatinib, a potent c-Abl TKI presently in clinical trials, to restore sensitivity to chemotherapeutic agents in multidrug-resistant cancer cells overexpressing ABCB1 and ABCG2.
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