The Escherichia coli rep mutation. X. Consequences of increased and decreased Rep protein levels
The Escherichia coli rep mutation. X. Consequences of increased and decreased Rep protein levels
复制标题
大肠杆菌代表突变。
DOI：
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
D. Denhardt
中科院分区：
文献类型：
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作者：
J. Colasanti;D. Denhardt
利用重组DNA技术研究了大肠杆菌rep基因功能的多样性。为了提高Rep蛋白的表达，将rep基因克隆到λpL启动子控制下的载体pKC 30中。通过修剪掉紧邻rep翻译起始位点上游的一部分DNA序列，我们能够在诱导后获得非常高水平的Rep蛋白。携带这种质粒的细胞没有显示出高浓度蛋白质的不良影响。为了确定细胞上不存在Rep蛋白的后果，使用同源重组技术删除基因的染色体拷贝。E.完全缺乏rep基因的大肠杆菌菌株证明，至少在实验室条件下野生型细胞中，Rep功能不是必需的。我们证实，在Rep功能的情况下，在指数生长的细胞中生长叉的平均数量增加;然而，Rep蛋白水平高于正常水平的增加并没有明显减少生长叉的数量。
SummaryRecombinant DNA techniques were used to study varibus aspects of rep gene function in Escherichia coli. In order to enhance expression of the Rep protein, the rep gene was cloned into the vector pKC30 under the control of the λpL promoter. By trimming away a portion of the DNA sequence immediately upstream of the translational start site of rep, we were able to obtain very high levels of Rep protein upon induction. Cells carrying such plasmids showed no ill effects from the high concentration of the protein. To ascertain the consequence of the absence of Rep protein on the cell, the chromosomal copy of the gene was deleted using a homologous recombination technique. The viability of E. coli strains completely lacking the rep gene proves that the Rep function is not essential, at least in wild-type cells under laboratory conditions. We confirmed that in the absence of Rep function there is an increase in the average number of growing forks in exponentially growing cells; augmentation of Rep protein levels above normal, however, did not detectably decrease the number of growing forks.
大肠杆菌 RNA 聚合酶 sigma 亚基的过表达和纯化。
影响因子：
3.5
作者：
Gribskov,M;Burgess,RR
通讯作者：
Burgess,RR