Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-6-13
pubmed:abstractText
Damage to DNA by reactive oxygen species may be a significant source of endogenous mutagenesis in aerobic organisms. Using an endogenous tonB gene as a mutation selective marker in Escherichia coli, we have examined whether endogenous oxidative mutagenesis can contribute to genetic instability. We have also used oxyR(+) and oxyR(-) strains to evaluate how hydrogen peroxide scavenging system can contribute to genetic instability. The highest mutation frequency induced by hydrogen peroxide was 3.8x10(-6) at 600 microM and 5.3 x 10(-6) at 40 microM in oxyR(+) and oxyR(-), respectively. Hydrogen peroxide induced minus frameshift mutations predominantly followed by transversions (G:C-->T:A, G:C-->C:G, and A:T-->T:A). The types and the nature of the mutations did not differ between strains. Frameshift mutations occurred at G:C and A:T sites equally, and in repeated and non-repeated sequences equally. It is evident that endogenous oxidative damage to DNA can increase the frequency of strand slippage intermediates occurring during DNA replication and contribute to genomic instability. Our results further indicate that oxyR regulon does not take part in the DNA-repair pathway against oxidative damage induced by hydrogen peroxide.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
306
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
570-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:12804603-Bacterial Proteins, pubmed-meshheading:12804603-Base Pair Mismatch, pubmed-meshheading:12804603-DNA, pubmed-meshheading:12804603-DNA Repair, pubmed-meshheading:12804603-DNA-Binding Proteins, pubmed-meshheading:12804603-Dose-Response Relationship, Drug, pubmed-meshheading:12804603-Escherichia coli, pubmed-meshheading:12804603-Escherichia coli Proteins, pubmed-meshheading:12804603-Frameshift Mutation, pubmed-meshheading:12804603-Hydrogen Peroxide, pubmed-meshheading:12804603-Membrane Proteins, pubmed-meshheading:12804603-Microsatellite Repeats, pubmed-meshheading:12804603-Models, Genetic, pubmed-meshheading:12804603-Mutagenesis, pubmed-meshheading:12804603-Mutation, pubmed-meshheading:12804603-Oxidative Stress, pubmed-meshheading:12804603-Repressor Proteins, pubmed-meshheading:12804603-Transcription Factors
pubmed:year
2003
pubmed:articleTitle
Hydrogen peroxide-induced microsatellite instability in the Escherichia coli K-12 endogenous tonB gene.
pubmed:affiliation
Department of Biomolecular Sciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't