Escherichia coli radC is deficient in the recA-dependent repair of X-ray-induced DNA strand breaks.
Escherichia coli K-12 cells incubated in buffer can repair most of their X-ray-induced DNA single-strand breaks, but additional single-strand breaks are repaired when the cells are incubated in growth medium. While the radC102 mutant was proficient at repairing DNA single-strand breaks in buffer (polA-dependent repair), it was partially deficient in repairing the additional single-strand breaks (or alkali-labile lesions) that the wild-type strain can repair in growth medium (recA-dependent repair), and this repair deficiency correlated with the X-ray survival deficiency of the radC strain. In studies using neutral sucrose gradients, the radC strain consistently showed a small deficiency in rejoining X-ray-induced DNA double-strand breaks, and it was deficient in restoring the normal sedimentation characteristics of the repaired DNA.
D003470:Culture Media; D004260:DNA Repair; D004269:DNA, Bacterial / Q000528:radiation effects*; D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects*; D007700:Kinetics; D009154:Mutation / Q000528:radiation effects*; D014965:X-Rays
D003470:Culture Media; D004269:DNA, Bacterial