Effects of sodium arsenite on single-strand DNA break formation and post-replication repair in E. coli following UV irradiation.

A non-lethal dose of sodium arsenite is found to inhibit the formation of single-strand DNA breaks in Escherichia coli WP2 wild-type and WP6 polA strains after UV irradiation. Inhibition of single-strand breakage follows a dose-dependent relationship with respect to increasing sodium arsenite concentration. ATP level in WP2 cells is decreased in the presence of sodium arasenite and therefore the inhibition of DNA break formation may be mediated through lowered ATP levels in the irradiated cells. In the presence of a non-lethal dose of sodium aresenite, post-replication repair in WP2 uvrA strains after UV irradation is also inhibited.