[Effect of insertional mutation in the cspA gene encoding the major cold-shock protein on radiation resistance of Escherichia coli].
Plasmid pCspA::Km carrying a cloned mutant allele of the cspA gene for the major Escherichia coli cold-shock protein CspA with an insertion of the kanamycin resistance gene cassette from transposon Tn903 into the core region of the coding sequence causes a 2.3-fold increase in radioresistance of wild-type E. coli cells (cspA+). The radioprotective effect of this plasmid is abolished or drastically reduced in mutants recA13 and rpoH15 defective in RecA protein and in induction of the heat-shock protein regulon, respectively. Plasmid pCspA::Km causes a 1.3-fold elevation in the resistance to gamma-irradiation of E. coli mutants with an intermediate level of radioresistance (Gamr445 and KS0160) but slightly diminishes resistance of a highly radiation-resistant Gamr445 mutant. In the chromosome of E. coli with normal DNA repair systems, the cspA::Km mutation in the homozygous state enhances resistance to the lethal effect of gamma-rays and UV light 2.9 and 1.4 times, respectively. These data suggest that the system of cold-shock proteins can modulate resistance of E. coli cells to the lethal effect of gamma-rays and UV light.
Verbenko
V N
VN
Petersburg Konstantinov Institute of Nuclear Physics, Russian Academy of Sciences, Gatchina, 188300 Russia. verbenko@omrb.pnpi.spb.ru
Kuznetsova
L V
LV
Smol'nikova
A V
AV
Kalinin
V L
VL
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000528:radiation effects; D002876:Chromosomes, Bacterial / Q000235:genetics; D003080:Cold Temperature; D004251:DNA Transposable Elements; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000235:genetics* / Q000528:radiation effects*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000528:radiation effects; D005720:Gamma Rays; D006579:Heterozygote; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D011938:Rec A Recombinases / Q000235:genetics; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; C062260:cold shock protein CS7.4, Bacteria; D011938:Rec A Recombinases