A c-di-AMP riboswitch controlling kdpFABC operon transcription regulates the potassium transporter system in Bacillus thuringiensis
A c-di-AMP riboswitch controlling kdpFABC operon transcription regulates the potassium transporter system in Bacillus thuringiensis
复制标题
控制 kdpFABC 操纵子转录的 c-di-AMP 核糖开关调节苏云金芽孢杆菌中的钾转运系统
DOI：
10.1038/s42003-019-0414-6
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发表时间：
2019
影响因子：
5.9
通讯作者：
He Jin
中科院分区：
文献类型：
--
作者：
Wang Xun;Cai Xia;Ma Hongdan;Yin Wen;Zhu Li;Li Xinfeng;Lim Heon M.;Chou Shan-Ho;He Jin
细菌细胞内K+水平受K+摄取和排出系统的严格控制。其中，KdpFABC是一种高亲和力的K+转运系统，其通常被KdpDE双组分系统激活以响应K+限制胁迫。然而，在缺乏kdpDE基因的细菌中，调控机制仍然不清楚。在此，我们报道了kdpFABC操纵子的转录受位于kdp转录物5′-非翻译区的环状二腺苷酸单磷酸（c-di-AMP）核糖开关的独特调控，c-di-AMP与核糖开关的结合促进其内在终止，从而阻断kdpFABC的转录。此外，发现细胞内c-di-AMP浓度在K+限制胁迫下降低，导致终止子上的转录通读以允许kdpFABC表达。这种调节元件主要存在于蜡状芽孢杆菌群中，并与影响多种关键细胞功能的K+和c-di-AMP稳态密切相关。
The intracellular K+ level in bacteria is strictly controlled by K+ uptake and efflux systems. Among these, KdpFABC is a high-affinity K+ transporter system that is generally activated by the KdpDE two-component system in response to K+ limitation stress. However, the regulatory mechanism remains obscure in bacteria lacking the kdpDE genes. Here we report that the transcription of a kdpFABC operon is distinctively regulated by a cyclic diadenylate monophosphate (c-di-AMP) riboswitch located at the 5′-untranslated region of kdp transcript, and binding of c-di-AMP to the riboswitch promotes its intrinsic termination that blocks the kdpFABC transcription. Further, the intracellular c-di-AMP concentration was found to decrease under the K+ limitation stress, leading to transcriptional read-through over the terminator to allow kdpFABC expression. This regulatory element is found predominantly in the Bacillus cereus group and correlate well with the K+ and c-di-AMP homeostasis that affects a variety of crucial cellular functions.