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Rrp17p Is a Eukaryotic Exonuclease Required for 5′ End Processing of Pre-60S Ribosomal RNA

Ribosomal processing requires a series of endo- and exonucleolytic steps for the production of mature ribosomes, of which most have been described. To ensure ribosome synthesis, 3′ end formation of rRNA uses multiple nucleases acting in parallel; however, a similar parallel mechanism had not been de...

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Detalles Bibliográficos
Autores principales: Oeffinger, Marlene, Zenklusen, Daniel, Ferguson, Angelica, Wei, Karen E., El Hage, Aziz, Tollervey, David, Chait, Brian T., Singer, Robert H., Rout, Michael P.
Formato: Texto
Lenguaje:English
Publicado: Cell Press 2009
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2806520/
https://www.ncbi.nlm.nih.gov/pubmed/20005841
http://dx.doi.org/10.1016/j.molcel.2009.11.011
Descripción
Sumario:Ribosomal processing requires a series of endo- and exonucleolytic steps for the production of mature ribosomes, of which most have been described. To ensure ribosome synthesis, 3′ end formation of rRNA uses multiple nucleases acting in parallel; however, a similar parallel mechanism had not been described for 5′ end maturation. Here, we identify Rrp17p as a previously unidentified 5′–3′ exonuclease essential for ribosome biogenesis, functioning with Rat1p in a parallel processing pathway analogous to that of 3′ end formation. Rrp17p is required for efficient exonuclease digestion of the mature 5′ ends of 5.8S(S) and 25S rRNAs, contains a catalytic domain close to its N terminus, and is highly conserved among higher eukaryotes, being a member of a family of exonucleases. We show that Rrp17p binds late pre-60S ribosomes, accompanying them from the nucleolus to the nuclear periphery, and provide evidence for physical and functional links between late 60S subunit processing and export.