The exceptional genomic content and genome organization of the Acidianus filamentous virus 1 (AFV1) that infects the hyperthermophilic archaeon Acidianus hospitalis suggest that this virus might exploit an unusual mechanism of genome replication. An analysis of replicative intermediates of the viral genome by two-dimensional (2D) agarose gel electrophoresis revealed that viral genome replication starts by the formation of a D-loop and proceeds via strand displacement replication. Characterization of replicative intermediates using dark-field electron microscopy, in combination with the 2D agarose gel electrophoresis data, suggests that recombination plays a key role in the termination of AFV1 genome replication through the formation of terminal loops. A terminal protein was found to be attached to the ends of the viral genome. The results allow us to postulate a model of genome replication that relies on recombination events for initiation and termination.
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http://dx.doi.org/10.1111/mmi.12630 | DOI Listing |
Genetics
January 2025
Institute for Evolution and Biodiversity, University of Münster, Münster 48149, Germany.
Transposable elements are DNA sequences that can move and replicate within genomes. Broadly, there are 2 types: autonomous elements, which encode the necessary enzymes for transposition, and nonautonomous elements, which rely on the enzymes produced by autonomous elements for their transposition. Nonautonomous elements have been proposed to regulate the numbers of transposable elements, which is a possible explanation for the persistence of transposition activity over long evolutionary times.
View Article and Find Full Text PDFNat Chem Biol
January 2025
Department of Gynecology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
The regressed arms of reversed replication forks exhibit structural similarities to one-ended double-stranded breaks and need to be protected against uncontrolled nucleolytic degradation. Here, we identify MSANTD4 (Myb/SANT-like DNA-binding domain-containing protein 4), a functionally uncharacterized protein that uniquely counters the replication protein A (RPA)-Bloom (BLM)/Werner syndrome helicase (WRN)-DNA replication helicase/nuclease 2 (DNA2) complex to safeguard reversed replication forks from detrimental degradation, independently of the breast cancer susceptibility proteins (BRCA1/2)-DNA repair protein RAD51 pathway. MSANTD4 specifically interacts with the junctions between single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) in DNA substrates harboring a 3' overhang, which resemble the structural features of regressed arms processed by WRN-DNA2.
View Article and Find Full Text PDFNat Commun
January 2025
National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China.
The Eurasian avian-like (EA) H1N1 swine influenza virus (SIV) possesses the capacity to instigate the next influenza pandemic, owing to its heightened affinity for the human-type α-2,6 sialic acid (SA) receptor. Nevertheless, the molecular mechanisms underlying the switch in receptor binding preferences of EA H1N1 SIV remain elusive. In this study, we conduct a comprehensive genome-wide CRISPR/Cas9 knockout screen utilizing EA H1N1 SIV in porcine kidney cells.
View Article and Find Full Text PDFSesame (Sesamum indicum L., 2n = 2× = 26) from the Pedaliaceae family is primarily grown for its high oil content, rich in unsaturated fatty acids like linoleic acid (LA) and alpha-linolenic acid (ALA). However, the molecular mechanisms of sesame oil accumulation remain poorly understood.
View Article and Find Full Text PDFMedicine (Baltimore)
November 2024
Department of Gastroenterology, The First Affiliated hospital of Harbin Medical University, Harbin, Heilongjiang, China.
Liver cirrhosis is a chronic disease caused by long-term inflammation and fibrosis of the liver. Early identification and intervention in liver cirrhosis have become an important goal for researchers to explore the influence of some metabolic factors on the risk of liver cirrhosis in terms of genetic susceptibility. Data from genome-wide association studies (GWASs) of fourteen metabolic factors and liver cirrhosis were obtained from publicly available databases.
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