EMD-32791

Single-particle
3.5 Å
EMD-32791 Deposition: 05/02/2022
Map released: 19/10/2022
Last modified: 26/06/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-32791

Cryo-EM structure of a yeast pre-40S ribosomal subunit - State Dis-E

EMD-32791

Single-particle
3.5 Å
EMD-32791 Deposition: 05/02/2022
Map released: 19/10/2022
Last modified: 26/06/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Saccharomyces cerevisiae
Sample: Yeast pre-40S ribosomal subunit
Fitted models: 7wtm (Avg. Q-score: 0.451)

Deposition Authors: Cheng J, La Venuta G, Lau B , Berninghausen O, Beckmann R, Hurt E , Beckmann R
In vitro structural maturation of an early stage pre-40S particle coupled with U3 snoRNA release and central pseudoknot formation.
Cheng J, La Venuta G, Lau B , Berninghausen O, Beckmann R, Hurt E
(2022) Nucleic Acids Res , 50 , 11916 - 11923
PUBMED: 36263816
DOI: doi:10.1093/nar/gkac910
ISSN: 1362-4962
ASTM: NARHAD
Abstract:
The transition of the 90S to the pre-40S pre-ribosome is a decisive step in eukaryotic small subunit biogenesis leading to a first pre-40S intermediate (state Dis-C or primordial pre-40S), where the U3 snoRNA keeps the nascent 18S rRNA locally immature. We in vitro reconstitute the ATP-dependent U3 release from this particle, catalyzed by the helicase Dhr1, and follow this process by cryo-EM revealing two successive pre-40S intermediates, Dis-D and Dis-E. The latter has lost not only U3 but all residual 90S factors including the GTPase Bms1. In vitro remodeling likewise induced the formation of the central pseudoknot, a universally conserved tertiary RNA structure that comprises the core of the small subunit decoding center. Thus, we could structurally reveal a key tertiary RNA folding step that is essential to form the active 40S subunit.