STRUCTURE AND STABILITY OF TN9-MEDIATED COINTEGRATES - EVIDENCE FOR 2 PATHWAYS OF TRANSPOSITION
STRUCTURE AND STABILITY OF TN9-MEDIATED COINTEGRATES - EVIDENCE FOR 2 PATHWAYS OF TRANSPOSITION
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DOI：
10.1016/0022-2836(82)90063-8
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发表时间：
1982-01-01
影响因子：
5.6
通讯作者：
CHANDLER, M
中科院分区：
文献类型：
--
作者：
GALAS, DJ;CHANDLER, M
转座子Tn9转座和共整合形成在大肠杆菌中的频率以几种不同的方式进行了检查。测定共整合物的稳定性。40个独立衍生的共整合分子的结构进行了物理分析。与转座因子Tn3不同，Tn9不通过专性共整合中间体转座。Tn9的转座可导致2种相互排斥的终产物：元件直接插入受体复制子（转座），或供体和受体复制子之间的融合（共整合形成）。这一结论是基于以下观察结果：虽然Tn9介导的共整合体非常稳定，但它们的形成速率低于转座频率。这一发现进行了讨论，在目前的模型换位。证据表明，清楚地证明了Tn9的化合物的性质。单个侧翼IS1元件在共整合形成中比整个Tn9转座子更活跃。在接近cam基因启动子的2个IS1元件中，一个比另一个更活跃，并且活性的差异可能是由于它们末端的核苷酸序列的差异。
The frequency of transposon Tn9 transposition and cointegrate formation in Escherichia coli were examined in several different ways. The stability of the cointegrates was determined. The structure of 40 independently derived cointegrate molecules was physically analyzed. Tn9, unlike the transposable element Tn3, does not transpose via an obligate cointegrate intermediate. Transposition of Tn9 may lead to 2, mutually exclusive, end-products: either direct insertion of the element into a recipient replicon (transposition), or fusion between donor and recipient replicons (cointegrate formation). This conclusion is based on observations that, while Tn9-mediated cointegrates are very stable, they are formed at a rate lower than the transposition frequency. This finding is discussed in terms of current models for transposition. Evidence that clearly demonstrates the compound nature of Tn9 is presented. The individual flanking IS1 elements are more active than the entire Tn9 transposon in cointegrate formation. Of the 2 IS1 elements that are proximal to the cam gene promoter, one is more active than the other and the difference in activity might be due to differences in nucleotide sequence at their extremities.