RNA regulation associated with mcr11-abmR locus in M. tuberculosis

项目摘要 结核分枝杆菌（Mtb）在感染过程中通过以下方式适应宿主相关环境： 调节基因表达。虽然转录因子（TF）是最广泛认可的 细菌基因表达的调节因子，调节细菌基因表达的基于RNA的因子， 结核病还不太清楚。这个项目的长期目标是确定基本的 Mtb的基因调控机制，特别关注RNA的作用。的 本项目的目的是确定与两种产物相关的核糖核酸调节机制， 结核分枝杆菌abmR-mcr11基因位点：原型sRNAMcr11和双功能RNA 结合TF AbmR，其是稳定mcr11表达所需的。我们将检验这个假设 Mcr 11的多个不同区域通过与靶标碱基配对来调节基因表达， mRNA序列，并表征Mtb中Mcr 11调控的影响。稳定表达 Mcr 11需要AbmR，AbmR结合ATP并通过以下方式促进Mtb的中心代谢： 抑制甲基萘醌生物合成基因menE的表达。我们认为RNA- 介导的AbmR寡聚化通过将其转化为39S复合物而降低其TF活性， 替代功能。关于RNA性质的高分辨率结构信息- AbmR复合物相互作用是鉴定AbmR复合物功能及其 结核分枝杆菌生物学中可能的作用。本研究的具体目标包括：目标1：定义 Mcr 11在生物、分子和遗传水平上的调节相互作用;以及目标2： 在结构和生物化学水平上表征RNA-AbmR相互作用的作用。 这些研究将结合联合收割机高分辨率低温电子显微镜和战略诱变， 生物化学和生物学方法来定义AbmR-RNA相互作用，同时提供 Mtb中RNA介导的调控机制的基本新见解。

Project summary Mycobacterium tuberculosis (Mtb) adapts to host-associated environments during infection by modulating gene expression. While transcription factors (TFs) are the most widely recognized regulators of bacterial gene expression, RNA-based factors that modulate gene expression in Mtb are less well understood. The long term goal of this project is to define fundamental mechanisms of gene regulation in Mtb, with a particular focus on the role of RNAs. The objective of this project is to define riboregulatory mechanisms associated with two products of the abmR-mcr11 gene locus in Mtb: the prototypical sRNA Mcr11 and the dual function RNA binding TF AbmR, which is required for stable mcr11 expression. We will test the hypothesis that multiple distinct regions of Mcr11 regulate gene expression by base pairing with target mRNA sequences, and characterize the impact of Mcr11 regulation in Mtb. Stable expression of Mcr11 requires AbmR, which binds ATP and contributes to central metabolism in Mtb by repressing expression of the menaquinone biosynthesis gene menE. We propose that RNA- mediated oligomerization of AbmR reduces its TF activity by converting it to a 39S complex with an alternate function. High resolution structural information regarding the nature of the RNA- AbmR complex interaction is critically needed to identify AbmR complex functions and its possible roles in Mtb biology. The specific aims of this research include: Aim 1: Define regulatory interactions of Mcr11 at the biological, molecular and genetic levels; and Aim 2: Characterize the roles of RNA-AbmR interactions at the structural and biochemical levels. These studies will combine high resolution cryo-electron microscopy with strategic mutagenesis, biochemical and biological approaches to define AbmR-RNA interactions while providing fundamental new insights into RNA-mediated regulatory mechanisms in Mtb.