Overproduction of the RecD polypeptide sensitizes Escherichia coli cells to gamma-radiation.
We investigated DNA metabolism in Escherichia coli cells carrying the multicopy recD+ plasmid (pKI13). In the presence of pKI13, the cellular level of the recD gene product (RecD polypeptide) is amplified at least 60-fold. Overproduction of the RecD polypeptide has no effect on UV repair and conjugational recombination. In contrast, high cellular levels of this polypeptide sensitize wild-type cells to gamma-radiation; also, they increase the rate of radiation-induced DNA degradation. A possible mechanism for the enhancement of gamma-ray-induced killing by large amounts of the RecD polypeptide is discussed.
Ruder Bosković Institute, Zagreb, Croatia, Yugoslavia.
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K
Brcić-Kostić
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Stojiljković
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Salaj-Smic
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Trgovcević
D004260:DNA Repair / Q000235:genetics*; D004269:DNA, Bacterial / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects*; D029968:Escherichia coli Proteins; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000235:genetics*; D005720:Gamma Rays; D015870:Gene Expression / Q000235:genetics; D007700:Kinetics; D010957:Plasmids / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics; D014466:Ultraviolet Rays
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D005090:Exodeoxyribonucleases; D043211:Exodeoxyribonuclease V; C468322:exodeoxyribonuclease V, E coli