In this report, we have characterized mutM mutant with respect to its ability to repair 8-hydroxyguanine (oh8Gua) in DNA. The oh8Gua DNA endonuclease activity in mutM strain was minimal as compared with that in the wild-type cells. The presence of oh8Gua in DNA of mutM was 6-fold that of the wild-type strain corresponding to a characteristically higher frequency of G•C → T•A transversions in this mutant strain. These results suggest that mutator phenotype of mutM is at least partially due to a spontaneous accumulation of oh8Gua resulting from a greatly reduced oh8Gua DNA endonuclease activity.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Oct 15 1992|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology