PPR proteins shed a new light on RNase P biology

RNA Biol. 2013;10(9):1457-68. doi: 10.4161/rna.25273. Epub 2013 Jun 19.


A fast growing number of studies identify pentatricopeptide repeat (PPR) proteins as major players in gene expression processes. Among them, a subset of PPR proteins called PRORP possesses RNase P activity in several eukaryotes, both in nuclei and organelles. RNase P is the endonucleolytic activity that removes 5' leader sequences from tRNA precursors and is thus essential for translation. Before the characterization of PRORP, RNase P enzymes were thought to occur universally as ribonucleoproteins, although some evidence implied that some eukaryotes or cellular compartments did not use RNA for RNase P activity. The characterization of PRORP reveals a two-domain enzyme, with an N-terminal domain containing multiple PPR motifs and assumed to achieve target specificity and a C-terminal domain holding catalytic activity. The nature of PRORP interactions with tRNAs suggests that ribonucleoprotein and protein-only RNase P enzymes share a similar substrate binding process.

Keywords: RNA binding protein; RNase P; evolution; pentatricopeptide repeat; tRNA maturation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • Chloroplasts / genetics
  • Chloroplasts / metabolism
  • Eukaryotic Cells / metabolism
  • Humans
  • Mitochondria / genetics
  • Mitochondria / metabolism
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Protein Conformation
  • Protein Structure, Tertiary
  • RNA Precursors / genetics
  • RNA Precursors / metabolism
  • RNA, Transfer / metabolism
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Ribonuclease P / genetics
  • Ribonuclease P / metabolism*
  • Trypanosoma brucei brucei / genetics
  • Trypanosoma brucei brucei / metabolism


  • Arabidopsis Proteins
  • Plant Proteins
  • RNA Precursors
  • RNA-Binding Proteins
  • RNA, Transfer
  • PRORP1 protein, Arabidopsis
  • Ribonuclease P