线粒体是细胞内有氧呼吸产生能量的细胞器。线粒体含有DNA，其基因组编码自身的rRNA、tRNA 及与与电子传递和氧化磷酸化相关的部分蛋白。线粒体RNA加工是线粒体产生功能蛋白必不可少的过程。许多人类线粒体疾病与RNA加工的缺陷有关。但我们对参与线粒体tRNA前体3'末端加工的核糖核酸酶P（mt-RNase P）的了解刚开始。本课题鉴定裂殖酵母mt-RNase P的组成成分，研究mt-RNase P中的RNA亚基和蛋白质亚基之间的相互作用、mt-RNase P如何识别底物以及mt-tRNA前体5'末端和3'末端加工顺序。此外，研究芽殖酵母、裂殖酵母、拟南芥及人的mt-RNase P中的蛋白质的功能保守性。这些研究结果不但能加深我们对mt-RNase P的进化和mt-RNase P对底物识别机制的了解，而且能帮助我们认识线粒体RNA整个加工过程及人类线粒体疾病。

Mitochondria are organelles that produce energy through aerobic respiration. Mitochondria contain their own genomes that encode rRNA、tRNA and proteins that are involved in electron transport oxidative phosphorylation. Mitochondrial RNA processing is the process that is essential for the production of functional mitochondrial proteins. It appears that many human mitochondrial diseases involve defects in RNA processing. However, only recently have we begun to understand mitochondrial ribonuclease P （mt-RNAse P）.In this project, we investigate the subunit composition of mt-RNase P from the fission yeast Schizosaccharomyces pombe,the interaction between the protein and RNA subuunits of S. pombe mt-RNase P,the substrate recognition of S. pombe mt-RNase P and the functional conservation of the protein subunit of mt-RNase P among Saccharomyces cerevisiae,S. pombe,Arabidopsis thaliana and humans.Our results should not only advance our understanding of the evolution and substrate recognition of of mt-RNase P, but also provide insigt into mitochondrial RNA processing and mitochondrial disease.