Ribonuclease P: the evolution of an ancient RNA enzyme

Crit Rev Biochem Mol Biol. Mar-Apr 2006;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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Base Sequence
  • Evolution, Molecular*
  • Humans
  • Models, Biological
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Protein Binding
  • RNA Precursors / metabolism
  • Ribonuclease P / chemistry
  • Ribonuclease P / genetics
  • Ribonuclease P / metabolism*
  • Ribonucleoproteins / metabolism*
  • Substrate Specificity


  • RNA Precursors
  • Ribonucleoproteins
  • Ribonuclease P