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 language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Apr 16 2002|
- Phosphorolytic enzymes
- tRNA processing
ASJC Scopus subject areas