6SNT

Yeast 80S ribosome stalled on SDD1 mRNA.

This is a non-PDB format compatible entry.

Summary for 6SNT

• Entry DOI: 10.2210/pdb6snt/pdb
• EMDB information: 10262
• Descriptor: Saccharomyces cerevisiae S288C 18S ribosomal RNA (RDN18-1), rRNA, 40S ribosomal protein S7-A, 40S ribosomal protein S8-A, ... (83 entities in total)
• Functional Keywords: 80s, stalling, sdd1, translation
• Biological source: Saccharomyces cerevisiae; More
• Total number of polymer chains: 81
• Total formula weight: 3165148.34

Authors

Tesina, P.,Buschauer, R.,Cheng, J.,Becker, T.,Beckmann, R. (deposition date: 2019-08-27, release date: 2020-03-04, Last modification date: 2020-04-22)

Primary citation

Matsuo, Y.,Tesina, P.,Nakajima, S.,Mizuno, M.,Endo, A.,Buschauer, R.,Cheng, J.,Shounai, O.,Ikeuchi, K.,Saeki, Y.,Becker, T.,Beckmann, R.,Inada, T.
RQT complex dissociates ribosomes collided on endogenous RQC substrate SDD1.
Nat.Struct.Mol.Biol., 27:323-332, 2020

PubMed Abstract: Ribosome-associated quality control (RQC) represents a rescue pathway in eukaryotic cells that is triggered upon translational stalling. Collided ribosomes are recognized for subsequent dissociation followed by degradation of nascent peptides. However, endogenous RQC-inducing sequences and the mechanism underlying the ubiquitin-dependent ribosome dissociation remain poorly understood. Here, we identified SDD1 messenger RNA from Saccharomyces cerevisiae as an endogenous RQC substrate and reveal the mechanism of its mRNA-dependent and nascent peptide-dependent translational stalling. In vitro translation of SDD1 mRNA enabled the reconstitution of Hel2-dependent polyubiquitination of collided disomes and, preferentially, trisomes. The distinct trisome architecture, visualized using cryo-EM, provides the structural basis for the more-efficient recognition by Hel2 compared with that of disomes. Subsequently, the Slh1 helicase subunit of the RQC trigger (RQT) complex preferentially dissociates the first stalled polyubiquitinated ribosome in an ATP-dependent manner. Together, these findings provide fundamental mechanistic insights into RQC and its physiological role in maintaining cellular protein homeostasis.

PubMed: 32203490
DOI: 10.1038/s41594-020-0393-9

Experimental method

ELECTRON MICROSCOPY (2.8 Å)