Structure and Function of RNase MRP

[00:79 . 49]核糖体是所有细胞的蛋白质合成机器，对细胞生长和存活至关重要。核糖体的生物发生与生长速度、发育甚至疾病和衰老有关。因此，了解核糖体的形成过程是很重要的。这些复杂细胞器的合成需要一系列的活动，包括前体rRNA转录物的加工、特定核苷酸的修饰以及rRNA与50-80种蛋白质的组装。核糖体生物发生的关键特征在从酵母到人类的所有真核生物中都是共享的，这使得人们可以从对模式生物的研究中学到的东西中做出概括。在这个项目中，选择酿酒酵母作为实验生物，因为它有完善的遗传操作系统。这些研究将集中在RNase MRP的结构和功能上，RNase MRP是一种酶，可以在小核糖体亚基和大核糖体亚基的序列之间切割内部转录间隔中的前体rRNA。这种核仁酶含有一个RNA亚基和九个蛋白质。RNase MRP的结构和作用机制尚不清楚。PI将使用系统发育序列比较、突变分析、免疫沉淀和蛋白质标记来分析每个蛋白质亚基和RNA亚基的区域如何对酶结构和底物特异性做出贡献。遗传方法将辅以RNA结构探测和RNA结构和蛋白质-RNA相互作用的计算机分析。最终目标是为RNase MRP的结构和功能提供一个模型。

0077949LindahlRibosomes, the protein-synthesizing machines of all cells, are essential for cellular growth and survival. The biogenesis of ribosomes has been related to growth rate, development, and even disease and aging. Therefore, it is important to understand the process of ribosome formation. The synthesis of these complex organelles requires a series of activities, including processing of the precursor rRNA transcript, modification of specific nucleotides, and assembly of rRNA with 50-80 proteins. The key features of ribosome biogenesis are shared in all eukaryotes from yeast to humans, allowing one to make generalizations from what has been learned in studies of model organisms. In this project, Saccharomyces cerevisiae has been chosen as the experimental organism because of its well-developed systems for genetic manipulation. These studies will focus on the structure and function of RNase MRP, an enzyme that cleaves the precursor rRNA in the Internal Transcribed Spacer between the sequences destined for small and large ribosomal subunits. This nucleolar enzyme contains one RNA subunit and nine proteins. The architecture and mechanism of action of RNase MRP are poorly understood. The PI will use phylogenetic sequence comparisons, mutant analysis, immunoprecipitation and protein tagging to analyze how each protein subunit and territories of the RNA subunit contribute to enzyme structure and substrate specificity. The genetic approach will be complemented with RNA structure probing and computer analysis of RNA structure and protein-RNA interactions. The final goal is to provide a model for the structure and function of RNase MRP.