Suppression of spontaneous and hydrogen peroxide-induced mutations by a MutT-type nucleotide pool sanitization enzyme, the Escherichia coli Orf135 protein
✍ Scribed by Hiroyuki Kamiya; Emiko Iida; Naoko Murata-Kamiya; Yoshihiro Yamamoto; Takeyoshi Miki; Hideyoshi Harashima
- Book ID
- 104460527
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 296 KB
- Volume
- 8
- Category
- Article
- ISSN
- 1356-9597
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✦ Synopsis
Abstract
Background: We recently found that the Escherichia coli Orf135 protein, a MutT‐type enzyme, hydrolysed 2‐hydroxy‐dATP (2‐OH‐dATP), and less efficiently, 8‐hydroxy‐dGTP.
Results: In this study, we examined the effects of the absence of the orf135 gene. Frequencies of spontaneous and H~2~O~2~‐induced mutations were two‐ to three‐fold higher in the orf135^‐^ strain than in the wild‐type strain. These mutations include various mutations involving a G:C→T:A transversion, the same type of mutation elicited by 2‐OH‐dATP. Over‐expression of the Orf135 protein suppressed mutations even in the wild‐type strain, as well as in the orf135^‐^ strain.
Conclusions: The mutator phenotype of bacteria lacking the Orf135 protein suggests that this protein is involved in the suppression of mutations induced by oxidized deoxynucleotides in vivo and that various MutT‐type enzymes contribute to nucleotide pool sanitization.