Hamilton L D, Mahler I, Grossman L
Basic Life Sci. 1975;5A:235-43. doi: 10.1007/978-1-4684-2895-7_31.
Excision repair of UV-damaged Bacillus subtilis transforming DNA has been carried out by a sequential enzyme system in vitro. Incision adjacent to the pyrimidine dimer in the DNA strand by correndonuclease II-initiated excision of the damage by the 5' in equilibrium 3'-directed exonuclease of the Micrococcus luteus DNA polymerase. Reinsertion of nucleotides into the gap in the strand by the DNA polymerase at 10 degrees C terminated in a single-strand break which was sealed by a polynucleotide ligase, thereby repairing the DNA strand. This restored biological activity to damaged DNA up to doses resulting in 60% inactivation of transforming activity. At higher doses, less repair was achieved, due to the development of double-strand breaks during the in vitro incision and excision steps.
紫外线损伤的枯草芽孢杆菌转化DNA的切除修复已在体外通过一个顺序酶系统进行。由核酸内切酶II在DNA链中嘧啶二聚体旁进行切口，引发损伤的切除，这一过程由藤黄微球菌DNA聚合酶的5'至3'平衡定向外切核酸酶完成。在10摄氏度时，DNA聚合酶将核苷酸重新插入链中的缺口，终止于一个单链断裂处，该断裂处由多核苷酸连接酶封闭，从而修复DNA链。这使受损DNA恢复了生物活性，直至达到导致转化活性60%失活的剂量。在更高剂量下，修复程度较低，这是由于在体外切口和切除步骤中双链断裂的出现。
