Walker Scott C, Engelke David R
Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0606, USA.
Crit Rev Biochem Mol Biol. 2006 Mar-Apr;41(2):77-102. doi: 10.1080/10409230600602634.
Ribonuclease P (RNase P) is an ancient and essential endonuclease that catalyses the cleavage of the 5' leader sequence from precursor tRNAs (pre-tRNAs). The enzyme is one of only two ribozymes which can be found in all kingdoms of life (Bacteria, Archaea, and Eukarya). Most forms of RNase P are ribonucleoproteins; the bacterial enzyme possesses a single catalytic RNA and one small protein. However, in archaea and eukarya the enzyme has evolved an increasingly more complex protein composition, whilst retaining a structurally related RNA subunit. The reasons for this additional complexity are not currently understood. Furthermore, the eukaryotic RNase P has evolved into several different enzymes including a nuclear activity, organellar activities, and the evolution of a distinct but closely related enzyme, RNase MRP, which has different substrate specificities, primarily involved in ribosomal RNA biogenesis. Here we examine the relationship between the bacterial and archaeal RNase P with the eukaryotic enzyme, and summarize recent progress in characterizing the archaeal enzyme. We review current information regarding the nuclear RNase P and RNase MRP enzymes in the eukaryotes, focusing on the relationship between these enzymes by examining their composition, structure and functions.
核糖核酸酶P（RNase P）是一种古老且必需的内切核酸酶，可催化从前体tRNA（pre-tRNA）中切割5'前导序列。该酶是仅有的两种在所有生命王国（细菌、古菌和真核生物）中都能找到的核酶之一。大多数形式的RNase P是核糖核蛋白；细菌酶含有一个催化RNA和一个小蛋白。然而，在古菌和真核生物中，该酶进化出了越来越复杂的蛋白质组成，同时保留了结构相关的RNA亚基。目前尚不清楚这种额外复杂性的原因。此外，真核RNase P已进化成几种不同的酶，包括一种核活性酶、细胞器活性酶，以及一种独特但密切相关的酶RNase MRP的进化，RNase MRP具有不同的底物特异性，主要参与核糖体RNA生物合成。在这里，我们研究了细菌和古菌RNase P与真核酶之间的关系，并总结了表征古菌酶的最新进展。我们回顾了关于真核生物中核RNase P和RNase MRP酶的当前信息，通过研究它们的组成、结构和功能来关注这些酶之间的关系。
