scholarly journals A highly conserved endonuclease activity present in Escherichia coli, bovine, and human cells recognizes oxidative DNA damage at sites of pyrimidines.

1987 ◽  
Vol 7 (1) ◽  
pp. 26-32 ◽  
Author(s):  
P W Doetsch ◽  
W D Henner ◽  
R P Cunningham ◽  
J H Toney ◽  
D E Helland
Keyword(s):  
Escherichia Coli ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Uv Light ◽  
Human Fibroblasts ◽  
Human Cells ◽  
Sequence Specificity ◽  
Endonuclease Activity ◽  
E Coli ◽  
Endonuclease Iii

We have compared the sites of nucleotide incision on DNA damaged by oxidizing agents when cleavage is mediated by either Escherichia coli endonuclease III or an endonuclease present in bovine and human cells. E. coli endonuclease III, the bovine endonuclease isolated from calf thymus, and the human endonuclease partially purified from HeLa and CEM-C1 lymphoblastoid cells incised DNA damaged with osmium tetroxide, ionizing radiation, or high doses of UV light at sites of pyrimidines. For each damaging agent studied, regardless of whether the E. coli, bovine, or human endonuclease was used, the same sequence specificity of cleavage was observed. We detected this endonuclease activity in a variety of human fibroblasts derived from normal individuals as well as individuals with the DNA repair deficiency diseases ataxia telangiectasia and xeroderma pigmentosum. The highly conserved nature of such a DNA damage-specific endonuclease suggests that a common pathway exists in bacteria, humans, and other mammals for the reversal of certain types of oxidative DNA damage.

A highly conserved endonuclease activity present in Escherichia coli, bovine, and human cells recognizes oxidative DNA damage at sites of pyrimidines

1987 ◽  
Vol 7 (1) ◽  
pp. 26-32
Author(s):  
P W Doetsch ◽  
W D Henner ◽  
R P Cunningham ◽  
J H Toney ◽  
D E Helland
Keyword(s):  
Escherichia Coli ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Uv Light ◽  
Human Fibroblasts ◽  
Human Cells ◽  
Sequence Specificity ◽  
Endonuclease Activity ◽  
E Coli ◽  
Endonuclease Iii

We have compared the sites of nucleotide incision on DNA damaged by oxidizing agents when cleavage is mediated by either Escherichia coli endonuclease III or an endonuclease present in bovine and human cells. E. coli endonuclease III, the bovine endonuclease isolated from calf thymus, and the human endonuclease partially purified from HeLa and CEM-C1 lymphoblastoid cells incised DNA damaged with osmium tetroxide, ionizing radiation, or high doses of UV light at sites of pyrimidines. For each damaging agent studied, regardless of whether the E. coli, bovine, or human endonuclease was used, the same sequence specificity of cleavage was observed. We detected this endonuclease activity in a variety of human fibroblasts derived from normal individuals as well as individuals with the DNA repair deficiency diseases ataxia telangiectasia and xeroderma pigmentosum. The highly conserved nature of such a DNA damage-specific endonuclease suggests that a common pathway exists in bacteria, humans, and other mammals for the reversal of certain types of oxidative DNA damage.

scholarly journals The Saccharomyces cerevisiae Homologues of Endonuclease III from Escherichia coli, Ntg1 and Ntg2, Are Both Required for Efficient Repair of Spontaneous and Induced Oxidative DNA Damage in Yeast

1999 ◽  
Vol 19 (5) ◽  
pp. 3779-3787 ◽  
Author(s):  
Ingrun Alseth ◽  
Lars Eide ◽  
Manuela Pirovano ◽  
Torbjørn Rognes ◽  
Erling Seeberg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
High Efficiency ◽  
Intracellular Localization ◽  
Genome Project ◽  
Yeast Genome ◽  
Enzyme Analysis ◽  
Endonuclease Iii

ABSTRACT Endonuclease III from Escherichia coli is the prototype of a ubiquitous DNA repair enzyme essential for the removal of oxidized pyrimidine base damage. The yeast genome project has revealed the presence of two genes in Saccharomyces cerevisiae,NTG1 and NTG2, encoding proteins with similarity to endonuclease III. Both contain the highly conserved helix-hairpin-helix motif, whereas only one (Ntg2) harbors the characteristic iron-sulfur cluster of the endonuclease III family. We have characterized these gene functions by mutant and enzyme analysis as well as by gene expression and intracellular localization studies. Targeted gene disruption of NTG1 and NTG2produced mutants with greatly increased spontaneous and hydrogen peroxide-induced mutation frequency relative to the wild type, and the mutation response was further increased in the double mutant. Both enzymes were found to remove thymine glycol and 2,6-diamino-4-hydroxy-5-N-methylformamidopyrimidine (faPy) residues from DNA with high efficiency. However, on UV-irradiated DNA, saturating concentrations of Ntg2 removed only half of the cytosine photoproducts released by Ntg1. Conversely, 5-hydroxycytosine was removed efficiently only by Ntg2. The enzymes appear to have different reaction modes, as judged from much higher affinity of Ntg2 for damaged DNA and more efficient borhydride trapping of Ntg1 to abasic sites in DNA despite limited DNA binding. Northern blot and promoter fusion analysis showed that NTG1 is inducible by cell exposure to DNA-damaging agents, whereas NTG2 is constitutively expressed. Ntg2 appears to be a nuclear enzyme, whereas Ntg1 was sorted both to the nucleus and to the mitochondria. We conclude that functions of both NTG1 and NTG2 are important for removal of oxidative DNA damage in yeast.

scholarly journals Transgenic Expression of RecA of the Spirochetes Borrelia burgdorferi and Borrelia hermsii in Escherichia coli Revealed Differences in DNA Repair and Recombination Phenotypes

2004 ◽  
Vol 186 (8) ◽  
pp. 2266-2274 ◽  
Author(s):  
Adrienne D. Putteet-Driver ◽  
Jianmin Zhong ◽  
Alan G. Barbour
Keyword(s):  
Escherichia Coli ◽  
Dna Damage ◽  
Homologous Recombination ◽  
Borrelia Burgdorferi ◽  
Uv Light ◽  
Plasmid Vector ◽  
Borrelia Hermsii ◽  
Transgenic Expression ◽  
E Coli ◽  
Transgenic Cells

ABSTRACT After unsuccessful attempts to recover a viable RecA-deficient mutant of the Lyme borreliosis agent Borrelia burgdorferi, we characterized the functional activities of RecA of B. burgdorferi, as well as RecA of the relapsing fever spirochete Borrelia hermsii and the free-living spirochete Leptospira biflexa, in a recA mutant of Escherichia coli. As a control, E. coli RecA was expressed from the same plasmid vector. DNA damage repair activity was assessed after exposure of the transgenic cells to UV light or the radiomimetic chemicals methyl methanesulfonate and mitomycin C. Recombination activity in the cells was assessed by using an assay for homologous recombination between repeats in the chromosome and by measuring the ability of the cells to foster lytic growth by red gam mutant bacteriophage λ. Overall, we found that transgenic cells with recA genes of B. burgdorferi, B. hermsii, and L. biflexa had approximately equivalent activities in promoting homologous recombination in the lacZ duplication assay, but cells with B. burgdorferi recA and, most notably, B. hermsii recA were significantly less capable than cells with L. biflexa recA or E. coli recA in responding to DNA damage or in facilitating plaque formation in the phage assay. The comparatively poor function of Borrelia recA in the latter set of assays may be the consequence of impaired coordination in the loading of the transgenic RecA by RecBCD and/or RecFOR in E. coli.

scholarly journals NEIL2 Protects against Oxidative DNA Damage Induced by Sidestream Smoke in Human Cells

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e90261 ◽  
Author(s):  
Altaf H. Sarker ◽  
Arpita Chatterjee ◽  
Monique Williams ◽  
Sabrina Lin ◽  
Christopher Havel ◽  
...  
Keyword(s):  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Human Cells ◽  
Sidestream Smoke

Mutagenesis and More: umuDC and the Escherichia coli SOS Response

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1599-1610 ◽  
Author(s):  
Bradley T Smith ◽  
Graham C Walker
Keyword(s):  
Escherichia Coli ◽  
Dna Damage ◽  
Cellular Response ◽  
Sos Response ◽  
Posttranslational Regulation ◽  
E Coli ◽  
Sos Mutagenesis ◽  
Induced Mutagenesis ◽  
Mechanistic Basis ◽  
Increase Cell Survival

Abstract The cellular response to DNA damage that has been most extensively studied is the SOS response of Escherichia coli. Analyses of the SOS response have led to new insights into the transcriptional and posttranslational regulation of processes that increase cell survival after DNA damage as well as insights into DNA-damage-induced mutagenesis, i.e., SOS mutagenesis. SOS mutagenesis requires the recA and umuDC gene products and has as its mechanistic basis the alteration of DNA polymerase III such that it becomes capable of replicating DNA containing miscoding and noncoding lesions. Ongoing investigations of the mechanisms underlying SOS mutagenesis, as well as recent observations suggesting that the umuDC operon may have a role in the regulation of the E. coli cell cycle after DNA damage has occurred, are discussed.

Effects of Water Source, Dilution, Storage, and Bacterial and Fecal Loads on the Efficacy of Electrolyzed Oxidizing Water for the Control of Escherichia coli O157:H7

2004 ◽  
Vol 67 (7) ◽  
pp. 1377-1383 ◽  
Author(s):  
S. M. L. STEVENSON ◽  
S. R. COOK ◽  
S. J. BACH ◽  
T. A. McALLISTER
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Storage Temperature ◽  
Uv Light ◽  
Tap Water ◽  
Organic Matter Content ◽  
Water Source ◽  
Deionized Water ◽  
Escherichia Coli O157 ◽  
E Coli

To evaluate the potential of using electrolyzed oxidizing (EO) water for controlling Escherichia coli O157:H7 in water for livestock, the effects of water source, electrolyte concentration, dilution, storage conditions, and bacterial or fecal load on the oxidative reduction potential (ORP) and bactericidal activity of EO water were investigated. Anode and combined (7:3 anode:cathode, vol/vol) EO waters reduced the pH and increased the ORP of deionized water, whereas cathode EO water increased pH and lowered ORP. Minimum concentrations (vol/vol) of anode and combined EO waters required to kill 104 CFU/ml planktonic suspensions of E. coli O157:H7 strain H4420 were 0.5 and 2.0%, respectively. Cathode EO water did not inhibit H4420 at concentrations up to 16% (vol/vol). Higher concentrations of anode or combined EO water were required to elevate the ORP of irrigation or chlorinated tap water compared with that of deionized water. Addition of feces to EO water products (0.5% anode or 2.0% combined, vol/vol) significantly reduced (P < 0.001) their ORP values to <700 mV in all water types. A relationship between ORP and bactericidal activity of EO water was observed. The dilute EO waters retained the capacity to eliminate a 104 CFU/ml inoculation of E. coli O157:H7 H4420 for at least 70 h regardless of exposure to UV light or storage temperature (4 versus 24°C). At 95 h and beyond, UV exposure reduced ORP, significantly more so (P < 0.05) in open than in closed containers. Bactericidal activity of EO products (anode or combined) was lost in samples in which ORP value had fallen to ≤848 mV. When stored in the dark, the diluted EO waters retained an ORP of >848 mV and bactericidal efficacy for at least 125 h; with refrigeration (4°C), these conditions were retained for at least 180 h. Results suggest that EO water may be an effective means by which to control E. coli O157:H7 in livestock water with low organic matter content.

Oxidative DNA damage and inflammatory responses in cultured human cells and in humans exposed to traffic-related particles

2014 ◽  
Vol 217 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Udomratana Vattanasit ◽  
Panida Navasumrit ◽  
Man Bahadur Khadka ◽  
Jantamas Kanitwithayanun ◽  
Jeerawan Promvijit ◽  
...  
Keyword(s):  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Inflammatory Responses ◽  
Human Cells ◽  
Cultured Human Cells

scholarly journals Characterization of Escherichia coli DNA Lesions Generated within J774 Macrophages

2000 ◽  
Vol 182 (18) ◽  
pp. 5225-5230 ◽  
Author(s):  
Eliana Schlosser-Silverman ◽  
Maya Elgrably-Weiss ◽  
Ilan Rosenshine ◽  
Ron Kohen ◽  
Shoshy Altuvia
Keyword(s):  
Escherichia Coli ◽  
Dna Damage ◽  
Respiratory Burst ◽  
Defense Mechanism ◽  
Dna Lesions ◽  
Intracellular Bacteria ◽  
Bacterial Killing ◽  
Strand Breaks ◽  
E Coli ◽  
Dna Strand

ABSTRACT Macrophages are armed with multiple oxygen-dependent and -independent bactericidal properties. However, the respiratory burst, generating reactive oxygen species, is believed to be a major cause of bacterial killing. We exploited the susceptibility of Escherichia coli in macrophages to characterize the effects of the respiratory burst on intracellular bacteria. We show that E. coli strains recovered from J774 macrophages exhibit high rates of mutations. We report that the DNA damage generated inside macrophages includes DNA strand breaks and the modification 8-oxo-2′-deoxyguanosine, which are typical oxidative lesions. Interestingly, we found that under these conditions, early in the infection the majority of E. coli cells are viable but gene expression is inhibited. Our findings demonstrate that macrophages can cause severe DNA damage to intracellular bacteria. Our results also suggest that protection against the macrophage-induced DNA damage is an important component of the bacterial defense mechanism within macrophages.

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