Transcription of integron-harboured gene cassette impacts integration efficiency in class 1 integron
Transcription of integron-harboured gene cassette impacts integration efficiency in class 1 integron
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整合子携带基因盒的转录影响 1 类整合子的整合效率
DOI：
10.1111/j.1365-2958.2011.07648.x
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发表时间：
2011-06-01
影响因子：
3.6
通讯作者：
Lu, Yuan
中科院分区：
文献类型：
--
作者：
Wei, Quhao;Jiang, Xiaofei;Lu, Yuan
1类整合子在细菌耐药基因的传播中起重要作用.通常，1类整合子由整合酶基因（intI 1）、重组位点（attI 1）和驱动下游基因盒转录的启动子（Pc）组成。有时，在Pc启动子下游存在第二启动子P2。已经定义了几种Pc变体和Pc-P2组合，它们显示出不同的转录强度，但整合子携带的基因盒的转录对整合效率的影响从未被全面研究。在这项研究中，基因盒整合到attI 1位点的下游的四个不同的Pc变体，以及它们与P2启动子的组合的频率进行了测量。结果表明，Pc启动子的强度与整合效率呈负相关，在相同的Pc启动子下，attI 1位点前加P2启动子会显著降低整合效率。我们的研究结果表明，整合子携带的基因盒的转录与外源基因盒的整合之间存在一定的关系。这两个相对独立的过程之间的相互关系可能有助于我们了解1类整合子的调节系统。
P>Class 1 integrons play important roles in the dissemination of antibiotic resistance genes among bacteria. Generally, class 1 integron consists of an integrase gene (intI1), a recombination site (attI1) and a promoter (Pc) that drives the transcription of the downstreamed gene cassettes. Occasionally, there is a second promoter P2 downstream of the Pc promoter. Several Pc variants and Pc-P2 combinations have been defined and they display different transcription strengths, but the influence of the transcription of integron-harboured gene cassette on the integration efficiency has never been comprehensively studied. In this study, the integration frequencies of gene cassettes into the attI1 sites that downstream of four different Pc variants as well as their combinations with P2 promoter were measured. The results showed that there was an inverse correlation between the strength of Pc promoter and the integration efficiency and, with the same Pc promoter, the integration efficiency was significantly decreased when a P2 promoter preceded the attI1 site. Our findings indicate there is a relationship between the transcription of integron-harboured gene cassette and the integration of exogenous gene cassettes. The interrelationship between these two relatively independent processes may throw a light on our understanding the regulation system of class 1 integron.