ATP-dependent DNA end recognition and nucleolytic processing are central functions of the Mre11/Rad50 (MR) complex in DNA double-strand break repair. However, it is still unclear how ATP binding and hydrolysis primes the MR function and regulates repair pathway choice in cells. Here,Methanococcus jannaschii MR-ATPγS-DNA structure reveals that the partly deformed DNA runs symmetrically across central groove between two ATPγS-bound Rad50 nucleotide-binding domains. Duplex DNA cannot access the Mre11 active site in the ATP-free full-length MR complex. ATP hydrolysis drives rotation of the nucleotide-binding domain and induces the DNA melting so that the substrate DNA can access Mre11. Our findings suggest that the ATP hydrolysis-driven conformational changes in both DNA and the MR complex coordinate the melting and endonuclease activity.
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http://dx.doi.org/10.15252/embj.201592462 | DOI Listing |
Viruses
December 2024
The Catholic University Liver Research Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.
Hepatitis B virus (HBV) can cause chronic infections, significantly increasing the risk of death from cirrhosis and hepatocellular carcinoma (HCC). A key player in chronic HBV infection is covalently closed circular DNA (cccDNA), a stable episomal form of viral DNA that acts as a persistent reservoir in infected hepatocytes and drives continuous viral replication. Despite the development of several animal models, few adequately replicate cccDNA formation and maintenance, limiting our understanding of its dynamics and the evaluation of potential therapeutic interventions targeting cccDNA.
View Article and Find Full Text PDFBiochem J
January 2025
Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.
The bacterial transcription terminator Rho is a hexameric ATP-dependent RNA helicase that dislodges elongating RNA polymerases. It has an N-terminal primary RNA binding site (PBS) on each subunit and a C-terminal secondary RNA binding site at the central channel. Here, we show that Rho also binds to linear longer double-stranded DNAs (dsDNA) and the circular plasmids non-specifically using its PBS.
View Article and Find Full Text PDFJ Clin Invest
January 2025
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.
ATP-dependent chromatin remodeling protein ATRX is an essential regulator involved in maintenance of DNA structure and chromatin state and regulation of gene expression during development. ATRX was originally identified as the monogenic cause of X-linked α-thalassemia mental retardation (ATR-X) syndrome. Affected individuals display a variety of developmental abnormalities and skeletal deformities.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 2025
State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China. Electronic address:
Mammalian SWI/SNF (mSWI/SNF) ATP-dependent chromatin remodeling complexes play critical roles in regulating gene expression and DNA accessibility, and more than 20 % of cancers have mutations in genes encoding chromatin remodeling complexes. The mSWI/SNF family comprises three distinct classes: canonical BAF (cBAF), PBAF, and non-canonical BAF (ncBAF). While the structures of cBAF and PBAF have been resolved by using cryo-electron microscopy (cryo-EM), the modular organization and assembly mechanism of ncBAF remain poorly understood.
View Article and Find Full Text PDFAnnu Rev Biophys
December 2024
Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA; email:
In this article I review mechanisms that underpin epigenetic inheritance of CpG methylation and histone H3 lysine 9 methylation (H3K9me) in chromatin in fungi and mammals. CpG methylation can be faithfully inherited epigenetically at some sites for a lifetime in vertebrates and, remarkably, can be propagated for millions of years in some fungal lineages. Transmission of methylation patterns requires maintenance-type DNA methyltransferases (DNMTs) that recognize hemimethylated CpG DNA produced by replication.
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