Effect of flash photoreactivation on Escherichia coli recA induction by ultraviolet light.
Excision-deficient Escherichia coli, carrying the gene for the photolyase on a multicopy plasmid, were irradiated with ultraviolet (UV) light then photoreactivated by illumination delivered from a camera flash unit. Such instantaneous illumination monomerizes only cyclobutane pyrimidine dimers already bound by the photolyase. Whereas the lethal effect of UV light and the number of C-to-T transition-type mutations induced by UV irradiation were both significantly reduced by subsequent irradiation with a single flash of light, single-flash photoreactivation did not reverse the induction of the recA gene by UV light. The results indicate, therefore, that non-photoreactivable DNA lesions play a role in recA induction.
Yamamoto
K
K
Biological Institute, Faculty of Science, Tohoku University, Sendai, Japan.
D004926:Escherichia coli / Q000235:genetics* / Q000528:radiation effects; D015964:Gene Expression Regulation, Bacterial / Q000528:radiation effects*; D008027:Light; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D011938:Rec A Recombinases / Q000235:genetics*; D013014:SOS Response, Genetics; D014466:Ultraviolet Rays
D011938:Rec A Recombinases