A protein subunit of human RNase P, Rpp14, and its interacting partner, OIP2, have 3′→5′ exoribonuclease activity

Taijiao Jiang, Sidney Altman

Research output: Contribution to journalArticle

16 Scopus citations


The processing of precursor tRNAs at their 5′ and 3′ termini is a fundamental event in the biosynthesis of tRNA. RNase P is generally responsible for endonucleolytic removal of a leader sequence of precursor tRNA to generate the mature 5′ terminus. However, much less is known about the RNase P counterparts or other proteins that are active at the tRNA 3′ terminus. Here we show that one of the human RNase P subunits, Rpp14, together with one of its interacting protein partners, OIP2, is a 3′→5′ exoribonuclease with a phosphorolytic activity that processes the 3′ terminus of precursor tRNA. Immunoprecipitates of a crude human RNase P complex can process both ends of precursor tRNA by hydrolysis, but purified RNase P has no exonuclease activity. Rpp14 and OIP2 may be part of an exosome activity.

Original languageEnglish (US)
Pages (from-to)5295-5300
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number8
StatePublished - Apr 16 2002



  • Exosome
  • Phosphorolytic enzymes
  • tRNA processing

ASJC Scopus subject areas

  • General

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