A 2'-phosphotransferase implicated in tRNA splicing is essential in Saccharomyces cerevisiae

J Biol Chem. 1997 May 16;272(20):13203-10. doi: 10.1074/jbc.272.20.13203.


The last step of tRNA splicing in the yeast Saccharomyces cerevisiae is catalyzed by an NAD-dependent 2'-phosphotransferase, which transfers the splice junction 2'-phosphate from ligated tRNA to NAD to produce ADP-ribose 1"-2" cyclic phosphate. We have purified the phosphotransferase about 28,000-fold from yeast extracts and cloned its structural gene by reverse genetics. Expression of this gene (TPT1) in yeast or in Escherichia coli results in overproduction of 2'-phosphotransferase activity in extracts. Tpt1 protein is essential for vegetative growth in yeast, as demonstrated by gene disruption experiments. No obvious binding motifs are found within the protein. Several candidate homologs in other organisms are identified by searches of the data base, the strongest of which is in Schizosaccharomyces pombe.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Gene Expression Regulation, Fungal*
  • Genes, Fungal*
  • Molecular Sequence Data
  • Phosphotransferases (Alcohol Group Acceptor) / genetics*
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism
  • RNA Splicing / genetics*
  • RNA, Fungal / genetics*
  • RNA, Transfer / genetics*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Alignment


  • RNA, Fungal
  • Saccharomyces cerevisiae Proteins
  • RNA, Transfer
  • Phosphotransferases (Alcohol Group Acceptor)
  • TPT1 protein, S cerevisiae