Base excision repair system suppresses mutagenesis caused by 8-hydroxy-dGTP in Escherichia coli

Base excision repair enzyme endonuclease III suppresses mutagenesis caused by 8-hydroxy-dGTP.

To examine whether base excision repair suppresses mutations induced by oxidized deoxyribonucleotide 5'-triphosphates in the nucleotide pool, 8-hydroxy-dGTP (8-OH-dGTP) and 2-hydroxy-dATP were introduced into Escherichia coli strains deficient in endonucleases III (Nth) and VIII (Nei) and MutY, and mutations in the chromosomal rpoB gene were analyzed. The spontaneous rpoB mutant frequency was a...

1 Effects of base excision repair proteins on mutagenesis by 8 - oxo - 7 , 8 - dihydroguanine ( 8 -

8-Oxo-7,8-dihydroguanine (8-oxo-Gua, also known as 8-hydroxyguanine) is a major base lesion that is generated by reactive oxygen species in both the DNA and nucleotide pool. The role of DNA glycosylases, which initiate base excision repair, in the mutagenic processes of 8-oxo-Gua in DNA and 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate (8-oxo-dGTP, also known as 8-hydroxy-2'-deoxyguanosin...

Involvement of specialized DNA polymerases in mutagenesis by 8-hydroxy-dGTP in human cells.

The mutagenicity of an oxidized form of dGTP, 8-hydroxy-2'-deoxyguanosine 5'-triphosphate (8-OH-dGTP), was examined using human 293T cells. Shuttle plasmid DNA containing the supF gene was first transfected into the cells, and then 8-OH-dGTP was introduced by means of osmotic pressure. The DNAs replicated in the cells were recovered and then transfected into Escherichia coli. 8-OH-dGTP induced ...

Case Report of Meningoencephalitis in Calves Caused by Escherichia coli

Abortive base-excision repair of radiation-induced clustered DNA lesions in Escherichia coli.

It has been postulated that ionizing radiation produces a unique form of cellular DNA damage called "clustered damages" or "multiply damaged sites". Here, we show that clustered DNA damages are indeed formed in Escherichia coli by ionizing radiation and are converted to lethal double-strand breaks during attempted base-excision repair. In wild-type cells possessing the oxidative DNA glycosylase...