5JPQ

Cryo-EM structure of the 90S pre-ribosome

Summary for 5JPQ

• Entry DOI: 10.2210/pdb5jpq/pdb
• EMDB information: 8143
• Descriptor: WD40 domain proteins, Nop1, rrp9, ... (36 entities in total)
• Functional Keywords: nuclear rnp, ribosome
• Biological source: Chaetomium thermophilum; More
• Total number of polymer chains: 56
• Total formula weight: 3984526.12

Authors

Turk, M.,Cheng, J.,Berninghausen, O.,Kornprobst, M.,Flemming, D.,Kos-Braun, I.C.,Kos, M.,Thoms, M.,Hurt, E.,Beckmann, R. (deposition date: 2016-05-04, release date: 2016-07-27, Last modification date: 2024-05-08)

Primary citation

Kornprobst, M.,Turk, M.,Kellner, N.,Cheng, J.,Flemming, D.,Kos-Braun, I.,Kos, M.,Thoms, M.,Berninghausen, O.,Beckmann, R.,Hurt, E.
Architecture of the 90S Pre-ribosome: A Structural View on the Birth of the Eukaryotic Ribosome.
Cell, 166:380-393, 2016

PubMed Abstract: The 90S pre-ribosome is an early biogenesis intermediate formed during co-transcriptional ribosome formation, composed of ∼70 assembly factors and several small nucleolar RNAs (snoRNAs) that associate with nascent pre-rRNA. We report the cryo-EM structure of the Chaetomium thermophilum 90S pre-ribosome, revealing how a network of biogenesis factors including 19 β-propellers and large α-solenoid proteins engulfs the pre-rRNA. Within the 90S pre-ribosome, we identify the UTP-A, UTP-B, Mpp10-Imp3-Imp4, Bms1-Rcl1, and U3 snoRNP modules, which are organized around 5'-ETS and partially folded 18S rRNA. The U3 snoRNP is strategically positioned at the center of the 90S particle to perform its multiple tasks during pre-rRNA folding and processing. The architecture of the elusive 90S pre-ribosome gives unprecedented structural insight into the early steps of pre-rRNA maturation. Nascent rRNA that is co-transcriptionally folded and given a particular shape by encapsulation within a dedicated mold-like structure is reminiscent of how polypeptides use chaperone chambers for their protein folding.

PubMed: 27419870
DOI: 10.1016/j.cell.2016.06.014

Experimental method

ELECTRON MICROSCOPY (7.3 Å)