Hadden C T
J Bacteriol. 1981 Jan;145(1):434-41. doi: 10.1128/jb.145.1.434-441.1981.
Repair of ultraviolet-irradiated transforming deoxyriboinucleic acid (DNA) in several strains of Bacillus subtilis was studied in order to determine the effects of excision repair and postreplication repair on transformation. Two mutations that cause a Uvr- and phenotype (uvr-1 and uvr-42) were shown to have strikingly different effects on repair of ultraviolet-irradiated transforming DNA. Genetic and kinetic evidence is presented to show that integrated DNA was apparently repaired by both excision and postreplication repair in wild-type and in uvr-1 recipients, although the latter excise pyrimidine dimers very slowly. In uvr-42 mutants, which are defective in incision at pyrimidine dimers, dimer-containing DNA was integrated. Postreplication repair apparently saved uvr-42 recipient cells from the lethal effects of integrated dimers, but the recombination events accompanying postreplication repair greatly reduced the linkage between closely linked genetic markers in the donor DNA. Repair of transforming DNA in a recG recipient, which does excision repair but not postreplication repair, was nearly as efficient as in wild-type cells. However, in this recipient linkage was altered only slightly, if at all, compared with wild-type cells. The apparent reduction in size of integrated regions of ultraviolet-irradiation transforming DNA probably results mainly from postreplication repair of larger integrated regions.
为了确定切除修复和复制后修复对转化的影响，对几种枯草芽孢杆菌菌株中紫外线照射的转化脱氧核糖核酸（DNA）的修复进行了研究。已证明导致Uvr-表型的两种突变（uvr-1和uvr-42）对紫外线照射的转化DNA的修复具有显著不同的影响。提供了遗传和动力学证据表明，整合的DNA在野生型和uvr-1受体中显然通过切除修复和复制后修复进行修复，尽管后者切除嘧啶二聚体的速度非常慢。在嘧啶二聚体切口有缺陷的uvr-42突变体中，含二聚体的DNA被整合。复制后修复显然使uvr-42受体细胞免受整合二聚体的致死效应，但伴随复制后修复的重组事件大大降低了供体DNA中紧密连锁的遗传标记之间的连锁。recG受体中的转化DNA修复，其进行切除修复但不进行复制后修复，几乎与野生型细胞一样有效。然而，与野生型细胞相比，在该受体中连锁即使有改变也非常轻微。紫外线照射的转化DNA整合区域大小的明显减小可能主要是由于较大整合区域的复制后修复。
