title: Ribonuclease P: the evolution of an ancient RNA enzyme.
abstract: 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.
authors.affiliation: Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0606, USA.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Walker
authors.forename: David R
authors.initials: DR
authors.lastname: Engelke
mesh_terms: D000818:Animals; D001483:Base Sequence; D019143:Evolution, Molecular; D006801:Humans; D008954:Models, Biological; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D012322:RNA Precursors / Q000378:metabolism; D043262:Ribonuclease P / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D012322:RNA Precursors; D012261:Ribonucleoproteins; D043262:Ribonuclease P