7WTZ

Cryo-EM structure of a human pre-40S ribosomal subunit - State RRP12-B2

Summary for 7WTZ

• Entry DOI: 10.2210/pdb7wtz/pdb
• EMDB information: 32806
• Descriptor: 18S rRNA, 40S ribosomal protein S28, Ubiquitin-40S ribosomal protein S27a, ... (35 entities in total)
• Functional Keywords: ribosome biogenesis, 40s ribosome, ribosome
• Biological source: Homo sapiens; More
• Total number of polymer chains: 34
• Total formula weight: 1524716.73

Authors

Cheng, J.,Lau, B.,Thoms, M.,Ameismeier, M.,Berninghausen, O.,Hurt, E.,Beckmann, R. (deposition date: 2022-02-05, release date: 2022-10-19, Last modification date: 2024-06-26)

Primary citation

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.
Nucleic Acids Res., 50:11924-11937, 2022

PubMed 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.

PubMed: 36321656
DOI: 10.1093/nar/gkac961

Experimental method

ELECTRON MICROSCOPY (3 Å)