Precursor tRNAs are transcribed with flanking and intervening sequences known to be processed by specific ribonucleases. Here, we show that transcription complexes of RNA polymerase III assembled on tRNA genes comprise RNase P that cleaves precursor tRNA and subsequently degrades the excised 5′ leader. Degradation is based on a 3′–5′ exoribonucleolytic activity carried out by the protein subunit Rpp14, as determined by biochemical and reverse genetic analyses. Neither reconstituted nor purified RNase P displays this magnesium ion-dependent, processive exoribonucleolytic activity. Markedly, knockdown of Rpp14 by RNA interference leads to a wide-ranging inhibition of cleavage of flanking and intervening sequences of various precursor tRNAs in extracts and cells. This study reveals that RNase P controls tRNA splicing complex and RNase Z for ordered maturation of nascent precursor tRNAs by transcription complexes.
|Original language||American English|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 2023|
Bibliographical notePublisher Copyright:
Copyright © 2023 the Author(s).
- RNA polymerase III
- RNase P
- transcription complex