Resolution of cointegrates between transposons gamma delta and Tn3 defines the recombination site.
Resolution of cointegrates between transposons gamma delta and Tn3 defines the recombination site.
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转座子 γ δ 和 Tn3 之间的共整合的解析定义了重组位点。
DOI：
10.1073/pnas.78.6.3428
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发表时间：
1981
影响因子：
11.1
通讯作者：
Reed,RR
中科院分区：
文献类型：
--
作者：
Reed,RR
基因相关的插入元件Gamma Delta和Tn3的移位被认为涉及两个步骤。在从一个复制子转座到另一个复制子的情况下，第一步是将父复制子和目标复制子融合，使元件在两个连接处以直接方向出现。在随后的反应中，通过特定部位的重组事件来分解共整合结构。我已经构建了两个质粒，每个携带包含内部分辨位点的伽马增量和Tn3片段。由Tn3或Gamma Delta编码的tnpR基因产物介导了这两个位点之间的分子内重组。这种重组的产物是一个杂交区域，它包含在交叉点融合的Gamma Delta和Tn3序列。对这些重组子的DNA序列分析表明，重组发生在Gamma Delta和Tn3之间精确同源的19个碱基对(BP)区域内。该位点位于tnpA基因起始前50bp的160个碱基的中心顺反子间区。因此，我的结果提出了一种对抑制物(TnpR)和转座酶(TnpA)基因的耦合调节以及转座中间产物的定点重组的模型。比较了Tn3/Gamma Delta重组系统和噬菌体lambda整合系统。
Transposition of the genetically related insertion elements gamma delta and Tn3 is thought to involve two steps. In the case of transposition from one replicon to another, the first step is fusion of the parent and target replicons with the element appearing in direct orientation at the two junctions. In a subsequent reaction, the cointegrate structure is resolved via a site-specific recombination event. I have constructed two plasmids, each carrying segments of gamma delta and Tn3, that contain the internal resolution site. The tnpR gene product encoded by either Tn3 or gamma delta mediates intramolecular recombination between these two sites. The product of this recombination is a hybrid region that contains gamma delta and Tn3 sequences fused at the point of crossover. DNA sequence analysis of such recombinants indicates that the recombination occurs within a 19-base-pair (bp) region of exact homology between gamma delta and Tn3. The site lies in the 160-bp center intercistronic region, 50 bp before the beginning of the tnpA gene. My results therefore suggest a model for the coupled regulation of the repressor (tnpR) and the transposase (tnpA) genes and site-specific recombination of transposition intermediates. The Tn3/gamma delta recombination system and bacteriophage lambda integration are compared.