A protein subunit of human RNase P, Rpp14, and its interacting partner, OIP2, have 3'-->5' exoribonuclease activity.
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.
Jiang
Taijiao
T
Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA.
Altman
Sidney
S
D002352:Carrier Proteins / Q000737:chemistry*; D002855:Chromatography, Thin Layer; D004247:DNA / Q000737:chemistry; D004722:Endoribonucleases / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D005095:Exoribonucleases / Q000737:chemistry; D063326:Exosome Multienzyme Ribonuclease Complex; D006367:HeLa Cells; D006801:Humans; D006868:Hydrolysis; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016337:RNA, Catalytic / Q000737:chemistry* / Q000378:metabolism; D012343:RNA, Transfer / Q000737:chemistry*; D012365:RNA, Transfer, Tyr / Q000737:chemistry; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D043262:Ribonuclease P; D013997:Time Factors
D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D016337:RNA, Catalytic; D012365:RNA, Transfer, Tyr; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D004247:DNA; D012343:RNA, Transfer; C456279:EXOSC8 protein, human; D004722:Endoribonucleases; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C468368:RPP14 protein, human; D043262:Ribonuclease P; C470865:ribonuclease P, E coli