EMD-4337

Single-particle
3.6 Å
EMD-4337 Deposition: 20/03/2018
Map released: 06/06/2018
Last modified: 15/05/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-4337

Cryo-EM structure of a late human pre-40S ribosomal subunit - State C

EMD-4337

Single-particle
3.6 Å
EMD-4337 Deposition: 20/03/2018
Map released: 06/06/2018
Last modified: 15/05/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Homo sapiens
Sample: Cryo-EM structure of a human pre-40S ribosomal subunit with bound PNO1, NOB1, TSR1, BYST, RIOK2 and LTV1
Fitted models: 6g18 (Avg. Q-score: 0.416)

Deposition Authors: Ameismeier M, Cheng J
Visualizing late states of human 40S ribosomal subunit maturation.
Ameismeier M, Cheng J, Berninghausen O, Beckmann R
(2018) Nature , 558 , 249 - 253
PUBMED: 29875412
DOI: doi:10.1038/s41586-018-0193-0
ISSN: 0028-0836
ASTM: NATUAS
Abstract:
The formation of eukaryotic ribosomal subunits extends from the nucleolus to the cytoplasm and entails hundreds of assembly factors. Despite differences in the pathways of ribosome formation, high-resolution structural information has been available only from fungi. Here we present cryo-electron microscopy structures of late-stage human 40S assembly intermediates, representing one state reconstituted in vitro and five native states that range from nuclear to late cytoplasmic. The earliest particles reveal the position of the biogenesis factor RRP12 and distinct immature rRNA conformations that accompany the formation of the 40S subunit head. Molecular models of the late-acting assembly factors TSR1, RIOK1, RIOK2, ENP1, LTV1, PNO1 and NOB1 provide mechanistic details that underlie their contribution to a sequential 40S subunit assembly. The NOB1 architecture displays an inactive nuclease conformation that requires rearrangement of the PNO1-bound 3' rRNA, thereby coordinating the final rRNA folding steps with site 3 cleavage.