EMD-35286
Cryo-EM structure of a Chaetomium thermophilum pre-60S ribosomal subunit - Dbp10-3
EMD-35286
Single-particle3.1 Å
Deposition: 07/02/2023
Map released: 17/05/2023
Last modified: 16/10/2024
Sample Organism:
Chaetomium thermophilum
Sample: pre-60S ribosome
Fitted models: 8i9w (Avg. Q-score: 0.441)
Deposition Authors: Lau B , Huang Z , Beckmann R , Hurt E , Cheng J
Sample: pre-60S ribosome
Fitted models: 8i9w (Avg. Q-score: 0.441)
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
(2023) EMBO Rep , 24 , e56910 - e56910
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.
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.