闪光光复活对大肠杆菌紫外线诱导recA的影响。

Effect of flash photoreactivation on Escherichia coli recA induction by ultraviolet light.

作者信息

Yamamoto K

机构信息

Biological Institute, Faculty of Science, Tohoku University, Sendai, Japan.

出版信息

FEMS Microbiol Lett. 1992 Nov 15;78(1):31-5. doi: 10.1016/0378-1097(92)90283-t.

DOI:10.1016/0378-1097(92)90283-t

PMID:1468615

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.

摘要

携带光裂合酶基因的多拷贝质粒的切除缺陷型大肠杆菌，先用紫外线（UV）照射，然后用相机闪光灯发出的光照进行光复活处理。这种瞬时光照只会使已经与光裂合酶结合的环丁烷嘧啶二聚体单体化。虽然紫外线的致死效应以及紫外线照射诱导的C到T转换型突变的数量都因随后的单次闪光照射而显著降低，但单次闪光光复活并不能逆转紫外线对recA基因的诱导。因此，结果表明，不可光复活的DNA损伤在recA诱导中起作用。