EMD-35290

Single-particle
2.7 Å
EMD-35290 Deposition: 07/02/2023
Map released: 17/05/2023
Last modified: 06/11/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-35290

Cryo-EM structure of a Chaetomium thermophilum pre-60S ribosomal subunit - State Puf6

EMD-35290

Single-particle
2.7 Å
EMD-35290 Deposition: 07/02/2023
Map released: 17/05/2023
Last modified: 06/11/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Chaetomium thermophilum
Sample: pre-60S ribosome
Fitted models: 8ia0 (Avg. Q-score: 0.531)

Deposition Authors: Lau B , Huang Z , Beckmann R , Hurt E , Cheng J
Mechanism of 5S RNP recruitment and helicase-surveilled rRNA maturation during pre-60S biogenesis.
Lau B , Huang Z , Kellner N, Niu S, Berninghausen O, Beckmann R , Hurt E , Cheng J
(2023) EMBO Rep , 24 , e56910 - e56910
PUBMED: 37129998
DOI: doi:10.15252/embr.202356910
ISSN: 1469-3178
Abstract:
Ribosome biogenesis proceeds along a multifaceted pathway from the nucleolus to the cytoplasm that is extensively coupled to several quality control mechanisms. However, the mode by which 5S ribosomal RNA is incorporated into the developing pre-60S ribosome, which in humans links ribosome biogenesis to cell proliferation by surveillance by factors such as p53-MDM2, is poorly understood. Here, we report nine nucleolar pre-60S cryo-EM structures from Chaetomium thermophilum, one of which clarifies the mechanism of 5S RNP incorporation into the early pre-60S. Successive assembly states then represent how helicases Dbp10 and Spb4, and the Pumilio domain factor Puf6 act in series to surveil the gradual folding of the nearby 25S rRNA domain IV. Finally, the methyltransferase Spb1 methylates a universally conserved guanine nucleotide in the A-loop of the peptidyl transferase center, thereby licensing further maturation. Our findings provide insight into the hierarchical action of helicases in safeguarding rRNA tertiary structure folding and coupling to surveillance mechanisms that culminate in local RNA modification.