Format

Send to

Choose Destination
EMBO J. 2018 Apr 3;37(7). pii: e98499. doi: 10.15252/embj.201798499. Epub 2018 Feb 19.

Structure of a eukaryotic cytoplasmic pre-40S ribosomal subunit.

Author information

1
Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland.
2
Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.
3
Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland.
4
Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland vpanse@imm.uzh.ch ban@mol.biol.ethz.ch.
5
Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland vpanse@imm.uzh.ch ban@mol.biol.ethz.ch.

Abstract

Final maturation of eukaryotic ribosomes occurs in the cytoplasm and requires the sequential removal of associated assembly factors and processing of the immature 20S pre-RNA Using cryo-electron microscopy (cryo-EM), we have determined the structure of a yeast cytoplasmic pre-40S particle in complex with Enp1, Ltv1, Rio2, Tsr1, and Pno1 assembly factors poised to initiate final maturation. The structure reveals that the pre-rRNA adopts a highly distorted conformation of its 3' major and 3' minor domains stabilized by the binding of the assembly factors. This observation is consistent with a mechanism that involves concerted release of the assembly factors orchestrated by the folding of the rRNA in the head of the pre-40S subunit during the final stages of maturation. Our results provide a structural framework for the coordination of the final maturation events that drive a pre-40S particle toward the mature form capable of engaging in translation.

KEYWORDS:

cryo‐EM; pre‐40S ribosome; ribosome; ribosome assembly; ribosome biogenesis

PMID:
29459436
PMCID:
PMC5881545
[Available on 2019-04-03]
DOI:
10.15252/embj.201798499

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center