DNA POLYMERASE-II IS ENCODED BY THE DNA DAMAGE-INDUCIBLE DINA GENE OF ESCHERICHIA-COLI
DNA POLYMERASE-II IS ENCODED BY THE DNA DAMAGE-INDUCIBLE DINA GENE OF ESCHERICHIA-COLI
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DOI：
10.1073/pnas.87.19.7663
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发表时间：
1990-10-01
影响因子：
11.1
通讯作者：
GOODMAN, MF
中科院分区：
文献类型：
--
作者：
BONNER, CA;HAYS, S;GOODMAN, MF
DNA聚合酶II的结构基因通过使用合成的含肌苷的寡核苷酸探针克隆，所述寡核苷酸探针对应于11个氨基酸，所述11个氨基酸通过对纯化的蛋白质的氨基末端进行测序来确定。标记的寡核苷酸特异性地杂交到DNA。来自Kohara保藏中心的克隆7 H9以及含有SOS调节的dinA基因的质粒pGW 511。测定了大约1400个碱基对的dinA序列。预测的dinA的氨基末端序列表明，该基因编码DNA聚合酶II。上游区的序列分析定位了与dinA启动子的-35区重叠的莱克萨结合位点，并且发现该启动子元件仅位于araD基因3“末端下游的两个核苷酸处。这些结果表明，在大肠杆菌染色体上的基因顺序是thr-dinA（pol II）-ara-leu，并且DNA聚合酶II结构基因以与araBAD操纵子相同的方向转录。基于预测的蛋白质的分析，我们已经确定了一个序列基序Asp-Xaa-Xaa-Ser-Leu-Tyr-Pro-Ser在DNA聚合酶II是高度保守的不同组的DNA聚合酶，其中包括那些从人类，酵母，疱疹病毒和牛痘病毒，和PRD 4和PRD 1。DNA聚合酶II是E.大肠杆菌中的表达表明它在DNA修复和/或诱变中起重要作用。
The structural gene for DNA polymerase II was cloned by using a synthetic inosine-containing oligonucleotide probe corresponding to 11 amino acids, which were determined by sequencing the amino terminus of the purified protein. The labeled oligonucleotide hybridized specifically to the .lambda. clone 7H9 from the Kohara collection as well as to plasmid pGW511 containing the SOS-regulated dinA gene. Approximately 1400 base pairs of dinA sequence were determined. The predicted amino-terminal sequence of dinA demonstrated that this gene encoded DNA polymerase II. Sequence analysis of the upstream region localized a LexA binding site overlapping the -35 region of the dinA promoter, and this promoter element was found to be only two nucleotides downstream from the 3'' end of the araD gene. These results demonstrate that the gene order is thr-dinA (pol II)-ara-leu on the Escherichia coli chromosome and that the DNA polymerase II structural gene is transcribed in the same direction as the araBAD operon. Based on the analysis of the predicted protein, we have identified a sequence motif Asp-Xaa-Xaa-Ser-Leu-Tyr-Pro-Ser in DNA polymerase II that is highly conserved among a diverse group of DNA polymerases, which include those from humans, yeast, herpes and vaccinia viruses, and phages T4 and PRD1. The demonstration that DNA polymerase II is a component of the SOS response in E. coli suggests that it plays an important role in DNA repair and/or mutagenesis.