RNA channelling by the eukaryotic exosome.
The eukaryotic exosome is a key nuclease for the degradation, processing and quality control of a wide variety of RNAs. Here, we report electron microscopic reconstructions and pseudo-atomic models of the ten-subunit Saccharomyces cerevisiae exosome in the unbound and RNA-bound states. In the RNA-bound structures, extra density that is visible at the entry and exit sites of the exosome channel indicates that a substrate-threading mechanism is used by the eukaryotic exosome. This channelling mechanism seems to be conserved in exosome-like complexes from all domains of life, and might have been present in the most recent common ancestor.
Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, London, UK.
Hélène
H
Malet
Maya
M
Topf
Daniel K
DK
Clare
Judith
J
Ebert
Fabien
F
Bonneau
Jerome
J
Basquin
Karolina
K
Drazkowska
Rafal
R
Tomecki
Andrzej
A
Dziembowski
Elena
E
Conti
Helen R
HR
Saibil
Esben
E
Lorentzen
D000595:Amino Acid Sequence; D055354:Exosomes / Q000378:metabolism* / Q000648:ultrastructure; D008958:Models, Molecular; D008969:Molecular Sequence Data; D021122:Protein Subunits / Q000378:metabolism; D012315:RNA Caps / Q000378:metabolism; D012331:RNA, Fungal / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism
D021122:Protein Subunits; D012315:RNA Caps; D012331:RNA, Fungal; D029701:Saccharomyces cerevisiae Proteins