The kinetics of degradation of DNA and RNA by H2O2

Massie, Harold R.; Samis, Harvey V.; Baird, Malcolm B.

doi:10.1016/0005-2787(72)90509-6

Cited by 112 publications

(53 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sites of cleavage by the two enzymes on DNA treated with hydrogen peroxide were also investigated. Treatment of DNA with hydrogen peroxide in the presence of trace amounts of metal ions was reported to produce several types of DNA damage (29). The relative reaction rates of these damages in order of decreasing magnitude were shown to be base modification, single-strand breaks, double-strand breaks, and cross-linking (29).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Substrate specificity of a mammalian DNA repair endonuclease that recognizes oxidative base damage.

Helland¹,

Doetsch²,

Haseltine³

1986

Mol. Cell. Biol.

View full text Add to dashboard Cite

The substrate specificity of a calf thymus endonuclease on DNA damaged by UV light, ionizing radiation, and oxidizing agents was investigated. End-labeled DNA fragments of defined sequence were used as substrates, and the enzyme-generated scission products were analyzed by using DNA sequencing methodologies. The enzyme wa? shown to incise damaged DNA at pyrimidine sites. The enzyme incised DNA damaged with UV light, ionizing radiation, osmium tetroxide, potassium permanganate, and hydrogen peroxide at cytosine and thymine sites. The substrate specificity of the calf thymus endonuclease was compared to that ofEscherichia coli endonuclease HI. Similar pyrimidine base damage specificities were found for both enzymes. These results define a highly conserved class of enzymes present in both procaryotes and eucaryotes that may mediate an important role in the repair of oxidative DNA damage.Oxidative damage to the genetic material is constant and inevitable. Reactive oxygen species are produced by normal metabolic processes and by ambient levels of ionizing radiation (1, 33). Damage to DNA by active oxygen species results in strand breakage and base modification (32). The mutagenic consequences of ionizing radiation and oxidative DNA damage in bacteria include base substitutions at both A*T and G-C pairs (19,27). In mammalian cells, similar events may lead to ionizing radiation-induced activation of protooncogenes (20). Oxygen radicals have been implicated as endogeneous initiators of the degenerative processes related to cancer, heart disease, and aging (1, 11). The primary defense in most organisms against oxidative damage from radicals is provided by a high concentration of reducing agents such as a glutathione and by enzymes that catalytically scavenge the intermediates of oxygen reduction (11,17). A secondary defense is composed of a series of enzymes that repair DNA strand breaks and base damage (28). Such enzymes are present in both procaryotes and eucaryotes and are thought to play a key role in the maintenance of the genetic stability of the organism.Several mammalian endonuclease activities have been described that recognize DNA damage induced by oxidizing agents, ionizing radiation, or high doses of UV light. Such enzymes are relatively small in size (25 to 30 kilodaltons), possess no divalent cation requirements, and have been partially purified from human lymphoblasts (8), fibroblasts (4), calf thymus (2), rat liver (36), and mouse plasmacytoma cells (31). These studies suggest that this group of DNA repair enzymes recognizes modified bases such as thymine glycol and a variety of ring-saturated, ring-cleaved, and ring-contracted products resulting from oxidative damage to DNA bases. In this regard, these enzymes are broadly similar to Escherichia coli endonuclease III. However, neither the sites of DNA scission nor the substrate specificities * Corresponding author. Here we report the base specificity of a calf thymus endonuclease activity. The calf thymus endonuclease was active in the presence of 10 mM E...

show abstract

Section: Resultsmentioning

confidence: 99%

“…DNA substrates were treated with 0.3 M hydrogen peroxide in the presence of 0.1 mM cupric sulfate at 37°C for 60 min (29 DNA sequencing reactions and gel electrophoresis. The purine (G+A), pyrimidine (C+T), or cytosine (C) basespecific DNA sequencing reactions (30) were run alongside each set of samples in all experiments.…”

Section: Enzymesmentioning

confidence: 99%

Substrate specificity of a mammalian DNA repair endonuclease that recognizes oxidative base damage.

Helland¹,

Doetsch²,

Haseltine³

1986

Mol. Cell. Biol.

View full text Add to dashboard Cite

show abstract

“…Since the modalities of action of heat are similar to those of H202 (12,26,33) and since expression of some heat shock genes is induced by H202 (28, 38), the sensitivity of htrD cells to H202 was investigated. The htrD insertion mutant was more sensitive to H202 than the wild-type parent ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Isolation and characterization of the Escherichia coli htrD gene, whose product is required for growth at high temperatures

1992

View full text Add to dashboard Cite

Those genes in Escherichia coli defined by mutations which result in an inability to grow at high temperatures are designated htr, indicating a high temperature requirement. A new htr mutant of E. coli was isolated and characterized and is designated htrD. The htrD gene has been mapped to 19.3 min on the E. coli chromosome. Insertional inactivation of htrD with a mini-TnlO element resulted in a pleiotropic phenotype characterized by a severe inhibition of growth at 42°C and decreased survival at 50°C in rich media. Furthermore, htrD cells were sensitive to H202. Growth rate analysis revealed that htrD cells grow very slowly in minimal media supplemented with amino acids. This inhibitory effect has been traced to the presence of cysteine in the growth medium. Further studies indicated that the rate of cysteine transport is higher in htrD cells relative to the wild type. All of these results, taken together, indicate that the htrD gene product may be required for proper regulation of intracellular cysteine levels and that an increased rate of cysteine transport greatly affects the growth characteristics of E. coli. The heat shock response is a highly conserved cellular response to environmental stress, especially rapid changes in temperature (for a review, see reference 30). In E. coli, about 20 genes are transiently expressed at increased levels following a shift up in growth temperature. These genes form a regulon under the coordinate control of the positive transcriptional regulator C32. At least some of the heat shock genes are essential for E. coli growth at all temperatures, indicating that these genes, and indeed the heat shock response itself, play a fundamental role in bacterial physiology.In order to better understand how E. coli survives and adapts to exposure to high temperatures, a study has been initiated to define new genes whose products are required for growth at high temperatures. Libraries of E. coli cells harboring transposon insertions were created at 30°C. These libraries were subsequently screened at 42°C for the inability to grow well at this higher temperature. The genes defined by these insertions are designated htr (for high temperature requirement). Some of the genes isolated by this method have been described and fall into two broad classes based upon regulation of expression. The first class of htr genes is composed of previously unidentifi ( heat shock genes and * Corresponding author. includes the htrA and htrC genes (22,32 MATERIALS AND METHODSBacteria, bacteriophages, and plasmids. The bacteria, bacteriophages, and plasmids used in this work are described in Table 1.Media and bacterial growth. Bacteria were routinely cultured in either L broth or M9 minimal medium (27). When required, antibiotics were added to the following final concentrations: kanamycin, 100 ,uglml; ampicillin, 50 ,ugIml; tetracycline, 15 ,ug/ml. Glucose and glycerol were added to a final concentration of 0.4% each. Sodium acetate was added to a concentration of 0.2%. Sucrose, when used for suppression of the H...

show abstract

“…The average amount of oxidative DNA damage occurring per cell per day is estimated to be about 10,000 in humans, and in rat, with a higher metabolic rate, about 100,000 (Ames et al, 1993). Most of these damages affect only one strand of the DNA, but a fraction, about 1-2%, are double-strand damages such as DSBs (Massie et al, 1972). These damages can be repaired accurately by HRR.…”

Section: During Mitosis and Meiosis Dna Damages Caused By Diverse Exmentioning

confidence: 99%

Meiosis as an Evolutionary Adaptation for DNA Repair

Bernstein¹,

Bernstein²,

Michod³

2011

DNA Repair

View full text Add to dashboard Cite

The kinetics of degradation of DNA and RNA by H2O2

Cited by 112 publications

References 18 publications

Substrate specificity of a mammalian DNA repair endonuclease that recognizes oxidative base damage.

Substrate specificity of a mammalian DNA repair endonuclease that recognizes oxidative base damage.

Isolation and characterization of the Escherichia coli htrD gene, whose product is required for growth at high temperatures

Meiosis as an Evolutionary Adaptation for DNA Repair

Contact Info

Product

Resources

About