Transcription is a molecular process that involves the synthesis of RNA chain into the 5ʹ–3ʹ direction, and simultaneously nascent RNA chain tends to form geometric structures, known as cotranscriptional folding. This folding determines the functional properties of RNA molecules and possibly has a critical role during the synthesis. This functioning includes the characterized properties of riboswitches and ribozymes, which are significant when the transcription rate is comparable to the cellular environment. This study reports a novel noncoding region important in the genetic expression of polyphosphate glucokinase (ppgk) in Mycobacterium tuberculosis. This noncoding element of ppgk gene undergoes cleavage activity during the transcriptional process in M.tuberculosis. We revealed that cleavage occurs within the nascent RNA, and the resultant cleaved 3ʹRNA fragment carries the Shine–Dalgarno (SD) sequence and expression platform. We concluded cotranscriptional processing at the noncoding region as the required mechanism for ppgk expression that remains constitutive within the bacterial environment. This study defines the molecular mechanism dependent on the transient but highly active structural features of the nascent RNA.

中文翻译：

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结核分枝杆菌 H37Rv 共转录调控多磷酸葡萄糖激酶基因表达

转录是一个分子过程，涉及 RNA 链向 5ʹ-3ʹ 方向合成，同时新生的 RNA 链倾向于形成几何结构，称为共转录折叠。这种折叠决定了 RNA 分子的功能特性，并可能在合成过程中发挥关键作用。这种功能包括核糖开关和核酶的特征特性，当转录速率与细胞环境相当时，这些特性很重要。本研究报告了一个新的非编码区，它对结核分枝杆菌中多磷酸葡萄糖激酶 (ppgk) 的基因表达很重要。ppgk 基因的这种非编码元件在结核分枝杆菌的转录过程中具有切割活性。我们发现切割发生在新生的 RNA 中，生成的切割 3ʹRNA 片段带有 Shine-Dalgarno (SD) 序列和表达平台。我们得出结论，非编码区的共转录处理是 ppgk 表达所需的机制，它在细菌环境中仍然是组成性的。这项研究定义了依赖于新生 RNA 的瞬时但高度活跃的结构特征的分子机制。