%0 Journal Article
%T Structure of the nuclear exosome captured on a maturing preribosome
%J -
%D 2018
%R 10.1126/science.aar5428
%X The RNA exosome complex processes and degrades a wide range of transcripts, including ribosomal RNAs (rRNAs). We used cryo¨Celectron microscopy to visualize the yeast nuclear exosome holocomplex captured on a precursor large ribosomal subunit (pre-60S) during 7S-to-5.8S rRNA processing. The cofactors of the nuclear exosome are sandwiched between the ribonuclease core complex (Exo-10) and the remodeled ¡°foot¡± structure of the pre-60S particle, which harbors the 5.8S rRNA precursor. The exosome-associated helicase Mtr4 recognizes the preribosomal substrate by docking to specific sites on the 25S rRNA, captures the 3¡ä extension of the 5.8S rRNA, and channels it toward Exo-10. The structure elucidates how the exosome forms a structural and functional unit together with its massive pre-60S substrate to process rRNA during ribosome maturation
%U http://science.sciencemag.org/content/360/6385/219