98%
921
2 minutes
20
The conserved MHF1-MHF2 (MHF) complex functions in the activation of the Fanconi anaemia pathway of the DNA damage response, in regulating homologous recombination, and in DNA replication fork maintenance. MHF facilitates the processing of multiple types of branched DNAs by the DNA translocase FANCM. Here we report the crystal structure of a human MHF-DNA complex that reveals the DNA-binding mode of MHF. The structure suggests that MHF prefers branched DNA over double-stranded DNA because it engages two duplex arms. Biochemical analyses verify that MHF preferentially engages DNA forks or various four-way junctions independent of the junction-site structure. Furthermore, genetic experiments provide evidence that the observed DNA-binding interface of MHF is important for cellular resistance to DNA damage. These results offer insights into how the MHF complex recognizes branched DNA and stimulates FANCM activity at such a structure to promote genome maintenance.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3967914 | PMC |
http://dx.doi.org/10.1038/ncomms3987 | DOI Listing |
Sci Rep
July 2025
Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, 840 05, Bratislava, Slovakia.
Helicases and endonucleases play crucial roles in genome maintenance by unwinding or cleaving various forms of DNA and RNA structures in order to facilitate essential biological processes, such as DNA replication and recombination. Here, we identified fission yeast Dbl2 as a potential interactor of several complexes that exhibit either helicase or endonuclease activity, namely Fml1-MHF, SCF, Rqh1-Top3-Rmi1, and Mus81-Eme1. In vitro, Dbl2 binds to DNA, with a preference for branched molecules, such as D-loops, mobile Holliday junctions, and fork structures, making it a good candidate to play a central role in modulating the activity of helicases and endonucleases during replication and recombination repair.
View Article and Find Full Text PDFSci Rep
May 2025
School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, China.
Underwater image quality often deteriorates, posing significant challenges in extracting underwater information and affecting advanced visual tasks, for instance, tasks in various fields such as oceanography, marine biology, underwater exploration, underwater archaeology, environmental monitoring, and marine engineering. To overcome these issues, many recent methods have attempted various techniques. Most of them focus solely on a single factor, such as visibility recovery or contrast enhancement, while neglecting the overall improvement of image quality.
View Article and Find Full Text PDFInorg Chem
March 2025
Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, White City, London W12 0BZ, U.K.
A series of boron, aluminum, and gallium difluoride complexes [{(ArNCMe)CH}MF] (M = B, Al, Ga) are reported as catalysts for the defluorofunctionalization of electron-deficient arenes. Thiodefluorination reactions between TMS-SPh and poly(fluorinated aromatics) proceed under forcing conditions. Evidence is presented for the fluoride entering the catalytic cycle through a metathesis reaction with TMS-SPh to form metal thiolate intermediates, e.
View Article and Find Full Text PDFCancers (Basel)
February 2025
HPB Unit, Department of Surgery, University Hospital of Ioannina, 45110 Ioannina, Greece.
The increasing prevalence of the spectrum of Steatotic Liver Disease (SLD), including Metabolic-Associated Steatotic Liver Disease (MASLD), Metabolic-Associated Steatohepatitis (MASH), and progression to Cirrhosis and Hepatocellular Carcinoma (HCC) has led to intense research in disease pathophysiology, with many studies focusing on the role of iron. Iron overload, which is often observed in patients with SLD as a part of metabolic hyperferritinaemia (MHF), particularly in the reticuloendothelial system (RES), can exacerbate steatosis. This imbalance in iron distribution, coupled with a high-fat diet, can further promote the progression of SLD by means of oxidative stress triggering inflammation and activating hepatic stellate cells (HSCs), therefore leading to fibrosis and progression of simple steatosis to the more severe MASH.
View Article and Find Full Text PDFAm J Bot
September 2024
School of Biological Sciences, University of Adelaide, Adelaide, 5005, South Australia, Australia.
Premise: The Cenozoic Macquarie Harbour Formation (MHF) hosts one of the oldest and southernmost post-Cretaceous fossil plant assemblages in Australia. Coinciding with the Early Eocene Climatic Optimum (EECO) and predating the breakup of Australia from Antarctica, it offers critical data to study the diversity and extent of the Austral Polar Forest Biome, and the floristic divergence between Australasia and South America resulting from the Gondwana breakup.
Methods: The micromorphology and macromorphology of new fossil plant compressions from the MHF were described and systematically analyzed.