Characterization of a Minimal Type of Promoter Containing the-10 Element and a Guanine at the-14 or-13 Position in Mycobacteria
Characterization of a Minimal Type of Promoter Containing the-10 Element and a Guanine at the-14 or-13 Position in Mycobacteria
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分枝杆菌中含有 10 元素和 14 或 13 位鸟嘌呤的最小类型启动子的表征
DOI：
10.1128/jb.00385-17
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发表时间：
2017
影响因子：
3.2
通讯作者：
Hu Yangbo
中科院分区：
文献类型：
--
作者：
Zhu Yan;Mao Chunyou;Ge Xingyi;Wang Zhongwei;Lu Pei;Zhang Yong;Chen Shiyun;Hu Yangbo
三个关键的启动子元件，即，−10、−35和T− 15 G − 14 N，由RNA聚合酶的σ亚基识别。其中，已知具有-10元件和-35或T-15 G-14 N的启动子可以有效地启动转录，但最近的系统分析已经在结核分枝杆菌中鉴定出一大组仅包含-10共有序列的启动子。这些启动子如何启动转录仍然知之甚少。在这里，我们表明，启动子含有-10元件和上游G位于-14或-13位置可以成功地启动分枝杆菌中的转录。重要的是，这种新型启动子在没有其他启动子共有序列的情况下是有活性的，这表明它是一种最小的启动子类型。在体外和体内分析中，启动子上游G的突变降低了它们与RNA聚合酶结合的效率和它们启动转录的能力。σ区域3.0中的谷氨酸对于识别G-14和G-13是必需的，并且在分枝杆菌中的主要和类似主要的σ因子中是保守的，这表明识别这种最小类型的启动子可能是转录起始的共同机制。在M.结核分枝杆菌在保守的-10元件上游含有G-14或G-13，并且已经使用-10共有序列和G-14或G-13预测了代表性分枝杆菌物种中的数千个启动子。总之，我们的研究提出了一个通用的机制，从一个最小的启动子在分枝杆菌，这也可能是适用于其他bacteria.IMPORTANCEIn识别经典的启动子在模式生物大肠杆菌的详细信息相反，很少有人知道转录是如何启动在人类病原体结核分枝杆菌。在这项研究中，我们在分枝杆菌中鉴定了一种新型启动子，它只需要一个-10共有序列和一个上游G-14或G-13。对于识别-10元件和上游G重要的残基在分枝杆菌物种的σ A和σ B中是保守的。根据这些特征，可以使用-10共有序列和G-14或G-13预测分枝杆菌中的数千个启动子，这表明这种新型启动子的转录可能是广泛的。我们的研究结果提供了有见地的信息，在分枝杆菌的启动子特性。
Three key promoter elements, i.e., −10, −35, and T−15G−14N, are recognized by the σ subunit of RNA polymerase. Among them, promoters with the −10 element and either −35 or T−15G−14N are known to initiate transcription efficiently, but recent systematic analyses have identified a large group of promoters in Mycobacterium tuberculosis that contain only a −10 consensus. How these promoters initiate transcription remains poorly understood. Here, we show that promoters containing the −10 element and an upstream G located at the −14 or −13 position can successfully initiate transcription in mycobacteria. Importantly, this new type of promoter is active in the absence of other promoter consensuses, suggesting that it is a minimal promoter type. Mutation of the upstream G in promoters decreased the efficiencies of their binding with RNA polymerase and their abilities to initiate transcription in bothin vitroandin vivoanalyses. A glutamic acid in σ region 3.0 is essential for recognizing G−14and G−13and is conserved in both principal and principal-like σ factors in mycobacteria, indicating that recognition of this minimal type of promoter might be a common mechanism for transcription initiation. Consistently, more than 70% of the identified promoters in M. tuberculosis contained G−14or G−13upstream of the conserved −10 element, and thousands of promoters in representative mycobacterial species have been predicted using the −10 consensus and G−14or G−13. Altogether, our study presents a universal mechanism for transcription initiation from a minimal promoter in mycobacteria, which might also be applicable to other bacteria.IMPORTANCEIn contrast to the detailed information for recognizing classic promoters in the model organism Escherichia coli, very little is known about how transcription is initiated in the human pathogen Mycobacterium tuberculosis. In this study, we characterized a new type of promoter in mycobacteria that requires only a −10 consensus and an upstream G−14or G−13. Residues important for recognizing the −10 element and the upstream G are conserved in σAand σBfrom mycobacterial species. According to such features, thousands of promoters in mycobacteria can be predicted using the −10 consensus and G−14or G−13, which suggests that transcription from this new type of promoter might be widespread. Our findings provide insightful information for characterizing promoters in mycobacteria.