Felzenszwalb I, Sargentini N J, Smith K C
Radiat Res. 1986 May;106(2):166-70.
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.
在缓冲液中孵育的大肠杆菌K-12细胞能够修复其大部分由X射线诱导产生的DNA单链断裂，但当细胞在生长培养基中孵育时，额外的单链断裂会得到修复。虽然radC102突变体在缓冲液中修复DNA单链断裂方面表现出色（依赖于polA的修复），但在修复野生型菌株在生长培养基中能够修复的额外单链断裂（或碱不稳定损伤）方面存在部分缺陷（依赖于recA的修复），并且这种修复缺陷与radC菌株的X射线存活缺陷相关。在使用中性蔗糖梯度的研究中，radC菌株在重新连接X射线诱导的DNA双链断裂方面始终表现出轻微缺陷，并且在恢复修复后DNA的正常沉降特性方面存在缺陷。
