The exosome: a conserved eukaryotic RNA processing complex containing multiple 3'-->5' exoribonucleases.
We identified a complex in S. cerevisiae, the "exosome," consisting of the five essential proteins Rrp4p, Rrp41p, Rrp42p, Rrp43p, and Rrp44p (Dis3p). Remarkably, four of these proteins are homologous to characterized bacterial 3'-->5' exoribonucleases; Rrp44p is homologous to RNase II, while Rrp41p, Rrp42p, and Rrp43p are related to RNase PH. Recombinant Rrp4p, Rrp44p, and Rrp41p are 3'-->5' exoribonucleases in vitro that have distributive, processive, and phosphorolytic activities, respectively. All components of the exosome are required for 3' processing of the 5.8S rRNA. Human Rrp4p is found in a comparably sized complex, and expression of the hRRP4 gene in yeast complements the rrp4-1 mutation. We conclude that the exosome constitutes a highly conserved eukaryotic RNA processing complex.
Mitchell
P
P
European Molecular Biology Laboratory, Heidelberg, Germany.
Petfalski
E
E
Shevchenko
A
A
Mann
M
M
Tollervey
D
D
D000595:Amino Acid Sequence; D005095:Exoribonucleases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D005816:Genetic Complementation Test; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009097:Multienzyme Complexes / Q000378:metabolism*; D009154:Mutation; D012323:RNA Processing, Post-Transcriptional / Q000502:physiology*; D012340:RNA, Ribosomal, 5.8S / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins
D005656:Fungal Proteins; D009097:Multienzyme Complexes; D012340:RNA, Ribosomal, 5.8S; C098788:RRP4 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D005095:Exoribonucleases