Contribution of nonconsensus base pairs within ArsR binding sequences toward ArsR-DNA binding and arsenic-mediated transcriptional induction
Contribution of nonconsensus base pairs within ArsR binding sequences toward ArsR-DNA binding and arsenic-mediated transcriptional induction
复制标题
ArsR 结合序列中非共有碱基对对 ArsR-DNA 结合和砷介导的转录诱导的贡献
DOI：
10.1186/s13036-019-0181-4
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发表时间：
2019-06-06
影响因子：
5.6
通讯作者：
Li, Xianqiang
中科院分区：
文献类型：
--
作者：
Chen, Xingjuan;Jiang, Xin;Li, Xianqiang
背景转录报告基因是细菌生物传感器中的关键组成部分，用于监测环境变化对报告基因的诱导或抑制。通过使用位置权重矩阵（PWM）模型产生的转录因子与其共有序列的相互作用对于其报告子的灵敏度至关重要。然而，最近的研究表明，PWM模型的基础上的独立贡献的个别共识碱基对蛋白质的相互作用往往是不够的，以解释复杂的调控，如非共识序列对蛋白质-DNA结合亲和力的影响。在本研究中，我们采用了一个更简单的原核砷阻遏物（ArsR）调控系统，以获得蛋白质-DNA识别。ArsR结合序列内的非共识碱基对ArsR-DNA结合和砷介导的转录inductions.ResultsWe构建了一系列砷响应的报告，每个包括两个副本的ArsR结合序列从不同的资源。我们发现，高砷介导的诱导特别需要从大肠杆菌的结合序列被放置在第一个结合序列，然而，没有这样的偏好被观察到的第二个结合序列，这可能是从嗜酸氧化亚铁硫杆菌，质粒R773，聚球藻，或arsR的核心结合序列。通过创建一系列在第二结合序列的非共有碱基对上存在差异的报告基因，我们观察到一些构建体与ArsR的结合较弱，而另一些构建体与ArsR的结合较强。最有趣的是，虽然这些报告显示了类似的结合亲和力ArsR，砷依赖的诱导显着different.ConclusionsThe结果表明，非共识碱基对蛋白质结合可能有深远的影响，也可能调制后结合功能。这些发现为基因表达的复杂调控提供了新的见解，并促进了基于转录因子的生物传感器的发展。
BackgroundA transcriptional reporter is the key component in bacterial biosensors which are employed to monitor the induction or repression of a reporter gene corresponding to environmental change. Interaction of a transcription factor with its consensus sequence generated by using a position weight matrix (PWM) model is crucial for its sensitivity of the reporter. However, recent studies suggest that PWM model based on independent contribution of individual consensus base pairs to protein interaction is often insufficient to explain complex regulation, such as the effect of nonconsensus sequences on the protein-DNA binding affinity. In the present study, we employed a simpler prokaryotic arsenic repressor (ArsR) regulation system to access the protein-DNA recognition. Contribution of nonconsensus base pairs within ArsR binding sequences toward ArsR-DNA binding and arsenic-mediated transcriptional induction was studied.ResultsWe constructed a series of arsenic responsive reporters, each comprising two copies of the ArsR binding sequences from different resources. We found that high arsenic-mediated induction specifically requires the binding sequence fromEscherichia colito be placed at the first binding sequence; however, no such preference was observed for the second binding sequence, which could be fromAcidithiobacillus ferrooxidans, plasmid R773,Synechococcus, or a core binding sequence ofarsR. By creating a series of reporters differed at the nonconsensus base pairs of the second binding sequence, we observed that some constructs bound weakly while others strongly to ArsR. Most interestingly, although a number of these reporters showed similar binding affinity to ArsR, their arsenic-dependent induction differed significantly.ConclusionsThe results indicated that nonconsensus base pairs could have profound influence on protein binding and may also modulate post-binding function. These findings provide new insights into the complex regulation of gene expression and facilitate the development of transcriptional reporter-based biosensors.