PDF(Pubmed)
Abstract：
The endoribonuclease RNase P is responsible for tRNA 5\' maturation in all domains of life. A unique feature of RNase P is the variety of enzyme architectures, ranging from dual- to multi-subunit ribonucleoprotein forms with catalytic RNA subunits to protein-only enzymes, the latter occurring as single- or multi-subunit forms or homo-oligomeric assemblies. The protein-only enzymes evolved twice: a eukaryal protein-only RNase P termed PRORP and a bacterial/archaeal variant termed homolog of Aquifex RNase P (HARP); the latter replaced the RNA-based enzyme in a small group of thermophilic bacteria but otherwise coexists with the ribonucleoprotein enzyme in a few other bacteria as well as in those archaea that also encode a HARP. Here we summarize the history of the discovery of protein-only RNase P enzymes and review the state of knowledge on structure and function of bacterial HARPs and eukaryal PRORPs, including human mitochondrial RNase P as a paradigm of multi-subunit PRORPs. We also describe the phylogenetic distribution and evolution of PRORPs, as well as possible reasons for the spread of PRORPs in the eukaryal tree and for the recruitment of two additional protein subunits to metazoan mitochondrial PRORP. We outline potential applications of PRORPs in plant biotechnology and address diseases associated with mutations in human mitochondrial RNase P genes. Finally, we consider possible causes underlying the displacement of the ancient RNA enzyme by a protein-only enzyme in a small group of bacteria.
摘要：
核糖核酸内切酶RNaseP负责生命所有域的tRNA5'成熟。RNaseP的一个独特特征是各种酶结构，从具有催化RNA亚基的双亚基到多亚基核糖核蛋白形式到仅蛋白质的酶，后者以单亚基或多亚基形式或同源寡聚装配体形式出现。仅蛋白质的酶进化了两次：仅真核蛋白质的RNaseP称为PRORP，而细菌/古细菌的变体称为AquifexRNaseP的同源物（HARP）；后者在一小撮嗜热细菌中取代了基于RNA的酶，但在其他一些细菌以及也编码HARP的古细菌中与核糖核蛋白酶共存。在这里，我们总结了发现仅蛋白质RNaseP酶的历史，并回顾了有关细菌HARP和真核PRORP的结构和功能的知识状况。包括人线粒体RNaseP作为多亚基PRORP的范例。我们还描述了PRORP的系统发育分布和进化，以及PRORP在真核树上传播以及向后生动物线粒体PRORP募集两个额外的蛋白质亚基的可能原因。我们概述了PRORP在植物生物技术中的潜在应用，并解决了与人类线粒体RNaseP基因突变相关的疾病。最后,我们考虑了在一小群细菌中仅有蛋白质的酶取代古代RNA酶的可能原因。
