Mechanism of action of small-molecule inhibitors of bacterial gene transcription.

在所有生物体中，一种名为RNAP的多组分蛋白质在基因表达活动中起着至关重要的作用。基因表达很重要，因为它最终有助于生物体的发育和生存。RNAP可以被看作是为基因信息提供了一个声音，而基因信息本身是沉默的。了解这种声音是如何被放大和压制的，是生物学和医学研究许多领域的一个关键的踏脚石。因此，RNAP是一种非常重要的蛋白质，直接影响所有生物的发育和生存。为了表达一个基因，RNAP必须首先与代表该基因的dna序列结合，并解开dna序列的成对链，以访问“模板dna链”，以“读取”基因中隐藏的信息。RNAP的几个活动部分，称为“活动部分”，有助于RNAP的DNA结合和DNA解绕活动，因此通常是调节RNAP活性的“控制点”。来自细菌（如大肠杆菌）的RNAP的活性通常是通过细菌RNAP的“可移动部分”控制的。有趣的是，感染和杀死细菌的病毒通常是通过制造非常小的蛋白质来实现的，这些蛋白质专门用于干扰细菌RNAP的“可移动部分”的正常功能，RNAP有助于DNA结合和DNA解绕活动。尽管对RNAP进行了40年的研究，但人们对RNAP的“可移动部分”如何影响基因表达知之甚少。本申请中提出的及时工作旨在研究(i) RNAP的两个“可移动部分”如何促进基因表达，以及（ii）细菌病毒衍生的小蛋白如何抑制细菌RNAP。该研究的结果将对生物学和医学研究的几个方面产生重要影响：了解细菌RNAP的“可移动部分”如何促进基因表达对于阐明基因表达的过程和机制方面非常重要，因为实验上易于处理的细菌RNAP是研究复杂生物体（如人类）中RNAP基因表达的极好模型。了解细菌病毒衍生的小蛋白如何抑制细菌RNAP具有重要意义，因为它们为评估靶标提供了新的切入点，并为开发新药提供了知识库，这些新药可以抑制细菌RNAP，从而控制细菌传染病的传播。

In all living organisms, a multi-part protein, called RNAP, plays a crucial role in an activity of called gene expression. Gene expression is important because it ultimately contributes to the development and survival of the living organism. The RNAP can be regarded as providing a voice to genetic information that, on its own, is silent. Learning how that voice is amplified - and shushed - is a critical stepping stone to many areas of biological and medical research. Thus, the RNAP is a very important protein that directly contributes to the development and survival of all living organisms. To express a gene, the RNAP, must first bind to the DNA-sequence that represents the gene and unwind the paired strands of the DNA-sequence to access the 'template-DNA-strand' to 'read' the information harboured in the gene. Several moving parts of the RNAP, called 'mobile parts' contribute to the DNA binding and DNA unwinding activities of the RNAP, and therefore are often 'control points' for regulating the activity of the RNAP. The activity of the RNAP from bacteria, such as Escherichia coli, is often controlled through the 'mobile parts' of the bacterial RNAP. Intriguingly, viruses which infect and kill bacteria, often do so by making very small proteins, specifically aimed to interfere with the normal functioning of the 'mobile parts' of the bacterial RNAP, which contribute to the DNA binding and DNA unwinding activities. Despite four decades of research on RNAP, very little is known about how the 'mobile parts' of the RNAP contribute to gene expression. The timely work proposed in this application is aimed at studying (i) how two 'mobile parts' of the RNAP contribute to gene expression and (ii) how bacterial virus derived small proteins inhibit the bacterial RNAP. The outcome of the proposed research will have important implications on several aspects of biological and medical research: Understanding how the 'mobile parts' of the bacterial RNAP contribute to gene expression is important to elucidate the process and mechanistic aspects of gene expression in general, since the experimentally easily tractable bacterial RNAP is an excellent model to study gene expression by RNAP in complex organisms, like humans. Understanding how bacterial virus derived small proteins inhibit the bacterial RNAP is significant because they provide a novel point of entry to evaluate targets and generate a knowledge-base for the development of new drugs, which can inhibit the bacterial RNAP and so control the spread of bacterial infectious diseases.