Plasmid pKM101, whose mucA and B genes endow cells with enhanced mutation frequency and enhanced resistance to far-ultraviolet radiation (FUV) (254 nm), had no influence on these properties when cells were damaged by near-ultraviolet radiation (NUV) (300-400 nm). Thus, NUV lesions did not lead to induction of SOS repair and subsequent expression of mucA and B genes on plasmid pKM101. Further, when cells were pre-irradiated with NUV and subsequently irradiated with FUV, there was a blockage of SOS repair, including the repair normally controlled by genes on pKM101.