Evidence for a specific regulation of recA gene transcription in Escherichia coli.
The kinetics of the recA, sfiA and umuDC genes transcription were studied during a double SOS-inducing treatment in Escherichia coli cells using several strains carrying lacZ gene fusions. A transient inhibition in recA, but not in sfiA or umuDC promoted beta-galactosidase synthesis was detected after successive UV-irradiations. Results obtained with a recA--lacZ fusion introduced in several DNA-repair mutants demonstrated that neither a lower LexA inactivation nor a decrease in the production of the inducing signal are the events through which the successive UV-irradiation promoted the arrest of recA transcription. On the contrary, a specific UV-dose-dependent delay appears to be the reason for the inhibition of the recA gene transcription in cells irradiated twice.
Villaverde
A
A
Department of Genetics and Microbiology, Autonomous University of Barcelona, Spain.
Gibert
I
I
Barbé
J
J
D000255:Adenosine Triphosphate / Q000378:metabolism; D004260:DNA Repair; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics*; D005786:Gene Expression Regulation / Q000528:radiation effects; D005798:Genes, Bacterial; D011938:Rec A Recombinases / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D013014:SOS Response, Genetics; D014158:Transcription, Genetic / Q000528:radiation effects; D014466:Ultraviolet Rays
D004274:DNA, Recombinant; D011993:Recombinant Fusion Proteins; D000255:Adenosine Triphosphate; D011938:Rec A Recombinases