DNA repair in Escherichia coli: the dual function of uvr genes.
It has been shown earlier that the starvation of E. coli for both amino-acids and thymine applied prior to UV irradiation inhibits pyrimidine dimer excision without affecting cell survival after UV irradiation. In such cells pyrimidine dimers are tolerated by a rather error-free process that depends on the activity of uvrB, recA and lexA genes. Data presented here show: (a) that the efficient toleration of unexcised dimers requires also the uvrA gene; (b) that the starvation increases the level of RecA protein about 4.7 times; (c) that the effect of starvation on subsequent pyrimidine dimer excision is reversed by a 2 h incubation in complete medium before the cells are UV irradiated. The data suggest that the uvrA, uvrB, recA, lexA dependent nonexcisional repair may be a pathway temporarily functioning in repeatedly damaged cells.
Masek
F
F
Cancer Research Institute, Slovak Academy of Sciences, Bratislava, Slovakia.
Fridrichova
I
I
Pirsel
M
M
Sedliaková
M
M
D000251:Adenosine Triphosphatases / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D004265:DNA Helicases; D004260:DNA Repair; D004269:DNA, Bacterial / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D011938:Rec A Recombinases / Q000032:analysis
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C058093:UvrB protein, E coli; D011938:Rec A Recombinases; C068631:UvrA protein, E coli; D000251:Adenosine Triphosphatases; D004265:DNA Helicases