The yeast tRNA splicing endonuclease: a tetrameric enzyme with two active site subunits homologous to the archaeal tRNA endonucleases

Cell. 1997 Jun 13;89(6):849-58. doi: 10.1016/s0092-8674(00)80270-6.


The splicing of tRNA precursors is essential for the production of mature tRNA in organisms from all major phyla. In yeast, the tRNA splicing endonuclease is responsible for identification and cleavage of the splice sites in pre-tRNA. We have cloned the genes encoding all four protein subunits of endonuclease. Each gene is essential. Two subunits, Sen2p and Sen34p, contain a homologous domain of approximately 130 amino acids. This domain is found in the gene encoding the archaeal tRNA splicing endonuclease of H. volcanii and in other Archaea. Our results demonstrate that the eucaryal tRNA splicing endonuclease contains two functionally independent active sites for cleavage of the 5' and 3' splice sites, encoded by SEN2 and SEN34, respectively. The presence of endonuclease in Eucarya and Archaea suggests an ancient origin for the tRNA splicing reaction.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibody Specificity
  • Archaea / enzymology
  • Archaea / genetics*
  • Bacterial Proteins / genetics
  • Binding Sites / genetics
  • Biological Evolution
  • Endoribonucleases / chemistry*
  • Endoribonucleases / genetics*
  • Endoribonucleases / immunology
  • Fungal Proteins / genetics
  • Genes, Fungal / physiology
  • Nucleic Acid Conformation
  • Protein Conformation
  • Protein Structure, Tertiary
  • RNA Precursors / chemistry
  • RNA Precursors / genetics
  • RNA Precursors / metabolism
  • RNA Splicing / physiology
  • Rabbits
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics*
  • Sequence Homology, Amino Acid


  • Bacterial Proteins
  • Fungal Proteins
  • RNA Precursors
  • Endoribonucleases
  • splicing endonuclease

Associated data

  • GENBANK/M32336