Effect of flash photoreactivation on Escherichia coli recA induction by ultraviolet light |
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Authors: | Kazuo Yamamoto |
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Affiliation: | Biological Institute, Faculty of Science, Tohoku University, Sendai, Japan. |
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Abstract: | 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. |
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Keywords: | Lipid Fatty acid Avermectin Streptomyces avermitilis |
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