Johnson R C, Reznikoff W S
Genetics. 1984 May;107(1):9-18. doi: 10.1093/genetics/107.1.9.
Transposition of Tn5 in Escherichia coli strains containing one or multiple copies of the transposable element was investigated. It was found that the overall frequency of transposition within a cell remained constant regardless of the number of copies of Tn5 present in that cell. Experiments measuring the transposition frequency of differentially marked Tn5s confirmed that the frequency of transposition of an individual Tn5 decreased proportionally with the total number of copies of the element present in a cell. The IS50R -encoded function, protein 2, which has previously been shown to be an inhibitor of transposition, is sufficient to mediate this inhibitory effect. The concentration of protein 2 in a cell appears to modulate the transposition of individual Tn5 elements in such a way that the overall transposition of Tn5 in a cell remains constant.
对含有一个或多个转座元件拷贝的大肠杆菌菌株中Tn5的转座情况进行了研究。结果发现，细胞内转座的总体频率保持恒定，而与该细胞中Tn5的拷贝数无关。测量不同标记的Tn5转座频率的实验证实，单个Tn5的转座频率与细胞中该元件的总拷贝数成比例下降。先前已证明IS50R编码的功能蛋白2是转座抑制剂，它足以介导这种抑制作用。细胞中蛋白2的浓度似乎以这样一种方式调节单个Tn5元件的转座，即细胞中Tn5的总体转座保持恒定。
