Department of Bioprocess Engineering and Biotechnology, School of Pharmaceutical Sciences, Universidade Estadual Paulista - Unesp, Rodovia Araraquara-Jau km1, Araraquara, 14800-903, Brazil.
Curr Microbiol. 2022 May 27;79(7):207. doi: 10.1007/s00284-022-02902-9.
Bacillus subtilis employs five purine riboswitches for the control of purine de novo synthesis and transport at the transcription level. All of them are formed by a structurally conserved aptamer, and a variable expression platform harboring a rho-independent transcription terminator. In this study, we characterized all five purine riboswitches under the context of active gene expression processes both in vitro and in vivo. We identified transcription pause sites located in the expression platform upstream of the terminator of each riboswitch. Moreover, we defined a correlation between in vitro transcription readthrough and in vivo gene expression. Our in vitro assay demonstrated that the riboswitches operate in the micromolar range of concentration for the cognate metabolite. Our in vivo assay showed the dynamics of the control of gene expression by each riboswitch. This study deepens the knowledge of the regulatory mechanism of purine riboswitches.
枯草芽孢杆菌利用五个嘌呤核糖开关在转录水平上控制嘌呤从头合成和运输。它们都由结构保守的适体和一个含有 rho 独立转录终止子的可变表达平台组成。在这项研究中，我们在体外和体内的活性基因表达过程中对所有五个嘌呤核糖开关进行了特征描述。我们在每个核糖开关终止子上游的表达平台中鉴定了转录暂停位点。此外，我们还定义了体外转录通读与体内基因表达之间的相关性。我们的体外实验表明，这些核糖开关在微摩尔浓度范围内对其互补代谢物起作用。我们的体内实验显示了每个核糖开关对基因表达的控制的动态变化。这项研究加深了对嘌呤核糖开关调控机制的认识。
