Structural and functional studies of RNase MRP RNP

项目摘要 本项目主要研究核糖核酸酶MRP的结构和功能。RNase MRP和 必需的和通用的位点特异性真核核糖核酸内切酶。它是一种450 kDa的多组分催化剂， 核糖核蛋白（RNP）与核糖核酸酶P有关，但它已进化为具有独特的底物特异性， 独特的细胞功能。RNase MRP参与多种RNA分子的代谢， 包括rRNA和一些mRNA。在人类中，改变的RNase MRP活性导致一系列的 发育障碍，通常会导致身材非常矮小，头发脆弱，易患 癌症和其他异常;引起这些问题的机制不被称为RNase MRP 仍在研究中。 该提案的具体目标是： 1.确定了S.酿酒酵母核糖核酸酶MRP全酶使用冷冻- 电子显微镜（cryo-EM）。 2.酵母RNase MRP与其底物相互作用的表征。 这一提议将揭示RNase MRP的结构及其与其RNase P祖先的分歧。它将 揭示了RNase MRP RNA和蛋白质在与各种各样的生物相互作用中的各自作用。 底物，并阐明RNase MRP底物识别和切割位点选择的机制， 为RNase MRP细胞功能的表征铺平了道路。这些研究将具有广泛的 超越RNase MRP/P领域的影响，揭示了蛋白质和RNA的相互作用， 复杂的RNP酶，并通过推进我们的结构，功能和进化的理解， 催化RNP。

Project Summary This project is focused on structural and functional studies of Ribonuclease (RNase) MRP. RNase MRP an essential and universal site-specific eukaryotic endoribonuclease. It is a 450 kDa multicomponent catalytic ribonucleoprotein (RNP) related to RNase P, but it has evolved to have a distinct substrate specificity and unique cellular functions. RNase MRP is involved in the metabolism of a wide range of RNA molecules, including rRNA and some mRNAs. In humans, altered RNase MRP activity results in a range of developmental disorders that typically lead to an extremely short stature, brittle hair, predisposition to cancers, and other abnormalities; the mechanisms causing these problems are not known as RNase MRP remains understudied. The specific aims of the proposal are: 1. Determination of the structural organizations of the S. cerevisiae RNase MRP holoenzyme using cryo- electron microscopy (cryo-EM). 2. Characterization of interactions of yeast RNase MRP with its substrates. This proposal will reveal the structure of RNase MRP and its divergence from its RNase P progenitor. It will uncover the respective roles of RNase MRP RNA and proteins in the interactions with a diverse range of substrates and clarify the mechanisms of RNase MRP substrate recognition and cleavage site selection, paving the way to the characterization of RNase MRP cellular functions. These studies will have a broad impact beyond the RNase MRP/P field by revealing the interplay of proteins and RNA in one of the most complex RNP enzymes, and by advancing our understanding of the structure, function, and evolution of catalytic RNPs.