抄録
Reactive oxygen spiecies cause a wide variety of oxidative modification in DNA, which include many types of base damage such as thymine glycol (Tg) and 7,8-dihydroxy-8-oxoguanine (8-oxoG). 8-oxoG mispairs without cytosine and Tg blocks DNA synthesis in vitro. Therefore, these base damages are cytotoxic and mutagenic. In Escherichia coli, Nth protein functions as a DNA N-glycosylase/AP lyase for these base damages. Nth protein removes 8-oxoG from 8-oxoG:A and 8-oxoG:G pairs, and the functions of Nth protein suppress G:C to T:A and G:C to C:G transversions. We recently revealed that the Nth protein also recognizes 5-hydroxymethyluracil and 5-formyluracil. In C. intestinalis, Nth homologues are not yet identified. In this study, we identified and characterized CiNth protein in vitro and in vivo.
