ABSTRACT
The bioluminescence induced by luciferases of marine bacteria promotes repair of UV damaged DNA of Escherichia coli AB1886 uvrA6. It is shown that bacterial photolyase that implements photoreactivation activity is the major contributor to DNA repair. However, the intensity of bioluminescence increasing induced by UV-irradiation (SOS-induction) in bacterial cells is not enough for efficient photoreactivation.
Subject(s)
Adenosine Triphosphatases/metabolism , DNA-Binding Proteins/metabolism , Escherichia coli Proteins/metabolism , Escherichia coli/genetics , Luciferases, Bacterial/metabolism , SOS Response, Genetics , Ultraviolet Rays , Adenosine Triphosphatases/genetics , Adenosine Triphosphatases/radiation effects , DNA-Binding Proteins/genetics , DNA-Binding Proteins/radiation effects , Escherichia coli/radiation effects , Escherichia coli Proteins/genetics , Escherichia coli Proteins/radiation effects , Luciferases, Bacterial/genetics , Luciferases, Bacterial/radiation effects , Photobacterium/enzymologyABSTRACT
The UV resistance of luminescent bacteria Escherichia coli AB1886 uvrA6 (pLeo1) containing the plasmid with luxCDABE genes of marine bacteria Photobacterium leiognathi is approximately two times higher than the UV resistance of non-luminous bacteria E. coli AB1886 uvrA6. Introduction of phr::kan(r) mutations (a defect in the functional activity of photolyase) into the genome of E. coli AB1886 uvrA6 (pLeo1) completely removes the high UV resistance of the cells. Therefore, photoreactivation that involves bacterial photolyase contributes mainly to the bioluminescence-induced DNA repair. It is shown that photoreactivating activity of bioluminescence of P. leiognathi is about 2.5 times lower compared with that one induced by a light source with λ > 385 nm. It is also shown that an increase in the bioluminescence intensity, induced by UV radiation in E. coli bacterial cells with a plasmid containing the luxCD ABE genes under RecA-LexA-regulated promoters, occurs only 25-30 min later after UV irradiation of cells and does not contribute to DNA repair. A quorum sensing regulatory system is not involved in the DNA repair by photolyase.
