EMD-32800

Single-particle
3.1 Å
EMD-32800 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-32800

Cryo-EM structure of a human pre-40S ribosomal subunit - State RRP12-A1 (with CK1)

EMD-32800

Single-particle
3.1 Å
EMD-32800 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: Homo sapiens
Sample: Yeast pre-40S ribosomal subunit
Fitted models: 7wtt (Avg. Q-score: 0.426)

Deposition Authors: Cheng J , Lau B , Thoms M, Ameismeier M, Berninghausen O, Hurt E , Beckmann R
The nucleoplasmic phase of pre-40S formation prior to nuclear export.
Cheng J , Lau B , Thoms M, Ameismeier M, Berninghausen O, Hurt E , Beckmann R
(2022) Nucleic Acids Res , 50 , 11924 - 11937
PUBMED: 36321656
DOI: doi:10.1093/nar/gkac961
ISSN: 1362-4962
ASTM: NARHAD
Abstract:
Biogenesis of the small ribosomal subunit in eukaryotes starts in the nucleolus with the formation of a 90S precursor and ends in the cytoplasm. Here, we elucidate the enigmatic structural transitions of assembly intermediates from human and yeast cells during the nucleoplasmic maturation phase. After dissociation of all 90S factors, the 40S body adopts a close-to-mature conformation, whereas the 3' major domain, later forming the 40S head, remains entirely immature. A first coordination is facilitated by the assembly factors TSR1 and BUD23-TRMT112, followed by re-positioning of RRP12 that is already recruited early to the 90S for further head rearrangements. Eventually, the uS2 cluster, CK1 (Hrr25 in yeast) and the export factor SLX9 associate with the pre-40S to provide export competence. These exemplary findings reveal the evolutionary conserved mechanism of how yeast and humans assemble the 40S ribosomal subunit, but reveal also a few minor differences.