Kazuki Matsubara, Shouta Ueda, Junpei Yamamoto, Shigenori Iwai, Narumi Shioi-Aoki, Arato Takedachi, Isao Kuraoka
The T7 gene 3 product, T7 endonuclease I, acts on various substrates with DNA structures, including Holliday junctions, heteroduplex DNAs, and single-mismatch DNAs. Genetic analyses have suggested the occurrence of DNA recombination, replication, and repair in E.coli. In this study, T7 endonuclease I digested UV-irradiated covalently closed circular plasmid DNA into linear and nicked plasmid DNA, suggesting that the enzyme generates single- and double-strand breaks (SSB and DSB). To further investigate the biochemical functions of T7 endonuclease I, we have analyzed endonuclease activity in UV-induced DNA substrates containing a single lesion, cyclobutane pyrimidine dimers (CPD), and 6-4 photoproducts (6-4PP)...
March 1, 2024: Journal of Biochemistry