Efficient repair of large DNA loops in Saccharomyces cerevisiae
Efficient repair of large DNA loops in Saccharomyces cerevisiae
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DOI：
10.1093/nar/29.20.4134
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发表时间：
2001-10-15
影响因子：
14.9
通讯作者：
Lahue, RS
中科院分区：
文献类型：
--
作者：
Corrette-Bennett, SE;Mohlman, NL;Lahue, RS
通过错配修复，可以有效地纠正小环错配。大循环的情况就不太清楚了。据报道，大环上的修复活动从非常低到相当有效。也不确定有多少环修复活动存在，以及为什么被保留。为了帮助解决这些问题，我们使用体内和体外实验研究了酿酒酵母的大环修复。含有1,16或38nt环的异双工的转化导致所有三种底物的> 90%修复。38碱基环的修复独立于错配修复（MR）和核苷酸切除修复（NER）关键基因的突变发生，与酵母中其他已报道的环修复功能不同。16碱基环的修正大部分与MR无关，表明大环修复在这种大小异源中占主导地位。哺乳动物和酵母大环修复的相似之处在于环二级结构的抑制作用以及确定的切口对环去除和环保留产物的相对比例的作用。这些观察结果表明，酵母中有一个强大的大环修复途径，不同于MR和NER，并且在哺乳动物中保守。
Small looped mispairs are efficiently corrected by mismatch repair. The situation with larger loops is less clear. Repair activity on large loops has been reported as anywhere from very low to quite efficient. There is also uncertainty about how many loop repair activities exist and whether why are conserved. To help address these issues, we studied large loop repair in Saccharomyces cerevisiae using in vivo and in vitro assays. Transformation of heteroduplexes containing 1, 16 or 38 nt loops led to > 90% repair for all three substrates. Repair of the 38 base loop occurred independently of mutations in key genes for mismatch repair (MR) and nucleotide excision repair (NER), unlike other reported loop repair functions in yeast. Correction of the 16 base loop was mostly independent of MR, indicating that large loop repair predominates for this size heterology. Similarities between mammalian and yeast large loop repair were suggested by the inhibitory effects of loop secondary structure and by the role of defined nicks on the relative proportions of loop removal and loop retention products. These observations indicate a robust large loop repair pathway in yeast, distinct from MR and NER, and conserved in mammals.