Livneh Z
Proc Natl Acad Sci U S A. 1986 Jul;83(13):4599-603. doi: 10.1073/pnas.83.13.4599.
Replication of UV-irradiated circular single-stranded phage M13 DNA by Escherichia coli RNA polymerase (EC 2.7.7.6) and DNA polymerase III holoenzyme (EC 2.7.7.7) in the presence of single-stranded DNA binding protein yielded full-length as well as partially replicated products. A similar result was obtained with phage G4 DNA primed with E. coli DNA primase, and phage phi X174 DNA primed with a synthetic oligonucleotide. The fraction of full-length DNA was several orders of magnitude higher than predicted if pyrimidine photodimers were to constitute absolute blocks to DNA replication. Recent models have suggested that pyrimidine photodimers are absolute blocks to DNA replication and that SOS-induced proteins are required to allow their bypass. Our results demonstrate that, under in vitro replication conditions, E. coli DNA polymerase III holoenzyme can insert nucleotides opposite pyrimidine dimers to a significant extent, even in the absence of SOS-induced proteins.
在单链DNA结合蛋白存在的情况下，大肠杆菌RNA聚合酶（EC 2.7.7.6）和DNA聚合酶III全酶（EC 2.7.7.7）对紫外线照射的环状单链噬菌体M13 DNA进行复制，产生了全长以及部分复制的产物。用大肠杆菌DNA引发酶引发的噬菌体G4 DNA，以及用合成寡核苷酸引发的噬菌体φX174 DNA也得到了类似结果。如果嘧啶光二聚体构成DNA复制的绝对障碍，那么全长DNA的比例将比预测的高几个数量级。最近的模型表明，嘧啶光二聚体是DNA复制的绝对障碍，并且需要SOS诱导的蛋白质来使其绕过。我们的结果表明，在体外复制条件下，即使没有SOS诱导的蛋白质，大肠杆菌DNA聚合酶III全酶也能在很大程度上在嘧啶二聚体相对处插入核苷酸。
