Download MendeleyArchitecture of the 90S Pre-ribosome: A Structural View on the Birth of the Eukaryotic Ribosome.
Kornprobst, M., Turk, M., Kellner, N., Cheng, J., Flemming, D., Kos-Braun, I., Kos, M., Thoms, M., Berninghausen, O., Beckmann, R., Hurt, E.(2016) Cell 166: 380-393
- PubMed: 27419870
- DOI: https://doi.org/10.1016/j.cell.2016.06.014
- Primary Citation of Related Structures:
5JPQ - 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.
Organizational Affiliation:
Biochemie-Zentrum der Universität Heidelberg, 69120 Heidelberg, Germany.
