Formamidopyrimidine-DNA glycosylase (Fpg) is a DNA repair enzyme that excises oxidized purines from damaged DNA. The Schiff base intermediate formed during this reaction between Escherichia coli Fpg and DNA was trapped by reduction with sodium borohydride, and the structure of the resulting covalently cross-linked complex was determined at a 2.1-A resolution. Fpg is a bilobal protein with a wide, positively charged DNA-binding groove. It possesses a conserved zinc finger and a helix-two turn-helix motif that participate in DNA binding. The absolutely conserved residues Lys-56, His-70, Asn-168, and Arg-258 form hydrogen bonds to the phosphodiester backbone of DNA, which is sharply kinked at the lesion site. Residues Met-73, Arg-109, and Phe-110 are inserted into the DNA helix, filling the void created by nucleotide eversion. A deep hydrophobic pocket in the active site is positioned to accommodate an everted base. Structural analysis of the Fpg-DNA complex reveals essential features of damage recognition and the catalytic mechanism of Fpg.
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http://dx.doi.org/10.1074/jbc.M202058200 | DOI Listing |
Talanta
February 2025
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China. Electronic address:
Food Funct
October 2024
Centre for Animal Sciences and Veterinary Studies (CECAV), University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal.
The integrity of the genome is under constant threat from both endogenous and exogenous factors that induce oxidative stress and accelerate ageing. The demand for natural and organic cosmetics is rising due to the harmful effects of synthetic genotoxic agents on human health and the environment. Elderberry ( L.
View Article and Find Full Text PDFFree Radic Biol Med
August 2024
Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Norway; Department of Clinical Service, Division of Cancer Medicine, Oslo University Hospital, Oslo, Norway.
DNA damage caused by oxidative reactions plays a crucial role in the pathogenesis of colorectal cancer (CRC). In a previous cross-sectional study, CRC patients diagnosed with regional disease (stage III) exhibited a higher level of DNA base oxidation in peripheral blood mononuclear cells (PBMCs) 2-9 months post-surgery compared to those with localized disease (stage I-II). To further explore this observation over time, the present study aimed to investigate DNA base oxidation in CRC patients with localized versus regional disease 6 and 12 months after the initial measurements.
View Article and Find Full Text PDFMutat Res Genet Toxicol Environ Mutagen
March 2024
Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000 Grenoble, France. Electronic address:
Preclinical and clinical studies have shown that molecular hydrogen (H) has anti-oxidant, anti-inflammatory, and anti-apoptotic properties. Safety data are available in the literature and acute toxicity has been tested in isolated cells and laboratory animals. We have evaluates the genotoxicity of H in vivo in rats after 72 h exposure, following the International Council for Harmonization guidelines ICH S2 (R1).
View Article and Find Full Text PDFDNA Repair (Amst)
February 2024
Rutgers Center for Lipid Research, Rutgers University, New Brunswick, NJ, USA; Center for Microbiome, Nutrition, and Health, New Jersey Institute for Food, Nutrition, and Health, Rutgers University, New Brunswick, NJ, USA; Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ, USA. Electronic address:
Oxidative stress-induced DNA base modifications, if unrepaired, can increase mutagenesis and genomic instability, ultimately leading to cell death. Cells predominantly use the base excision repair (BER) pathway to repair oxidatively-induced non-helix distorting lesions. BER is initiated by DNA glycosylases, such as 8-oxoguanine DNA glycosylase (OGG1), which repairs oxidatively modified guanine bases, including 7,8-dihydro-8-oxoguanine (8-oxoG) and ring-opened formamidopyrimidine lesions, 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG).
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