Molecular actions of Escherichia coli MutT for control of spontaneous mutagenesis

Daiki Setoyama, Riyoko Ito, Yasumitsu Takagi, Mutsuo Sekiguchi

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


MutT protein of Escherichia coli hydrolyzes oxidized guanine nucleotides, 8-oxo-dGTP and 8-oxoGTP, to the corresponding monophosphates, thereby preventing misincorporation of 8-oxoguanine into DNA and RNA, respectively. Although the biological significance of the MutT has been established, how MutT protein actually works in vivo remains to be elucidated. The current study shows the molecular behavior of the MutT protein in vivo and in vitro with special reference to control of spontaneous mutagenesis. A single E. coli cell carries about 70-75 molecules of the MutT protein and that this number does not change even when the cells were cultured in anaerobic and hyper-oxidative conditions. Conditional gene silencing analyses revealed that about a half number of MutT molecules are needed for keeping the spontaneous mutation frequency at the normal level. The MutT functions are not needed under anaerobic condition, yet the level of the MutT protein in cell is kept constant, probably for preparing for sudden changes of oxygen pressure. There is a possibility that MutT functions in close association with other proteins, and evidence is presented that MutT protein can interact with some proteins in vivo.

Original languageEnglish
Pages (from-to)9-14
Number of pages6
JournalMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
Issue number1-2
Publication statusPublished - Feb 10 2011
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Genetics
  • Health, Toxicology and Mutagenesis


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