8AGZ

Yeast RQC complex in state with the RING domain of Ltn1 in the OUT position

This is a non-PDB format compatible entry.

Summary for 8AGZ

• Entry DOI: 10.2210/pdb8agz/pdb
• EMDB information: 15428
• Descriptor: 60S ribosomal protein L15-A, 60S ribosomal protein L24-A, 60S ribosomal protein L25, ... (56 entities in total)
• Functional Keywords: ribosome-associated quality control, nemf, listerin, cat tailing, translation
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Total number of polymer chains: 54
• Total formula weight: 2401272.44

Authors

Tesina, P.,Buschauer, R.,Beckmann, R. (deposition date: 2022-07-20, release date: 2023-03-08, Last modification date: 2024-10-09)

Primary citation

Tesina, P.,Ebine, S.,Buschauer, R.,Thoms, M.,Matsuo, Y.,Inada, T.,Beckmann, R.
Molecular basis of eIF5A-dependent CAT tailing in eukaryotic ribosome-associated quality control.
Mol.Cell, 83:607-621.e4, 2023

PubMed Abstract: Ribosome-associated quality control (RQC) is a conserved process degrading potentially toxic truncated nascent peptides whose malfunction underlies neurodegeneration and proteostasis decline in aging. During RQC, dissociation of stalled ribosomes is followed by elongation of the nascent peptide with alanine and threonine residues, driven by Rqc2 independently of mRNA, the small ribosomal subunit and guanosine triphosphate (GTP)-hydrolyzing factors. The resulting CAT tails (carboxy-terminal tails) and ubiquitination by Ltn1 mark nascent peptides for proteasomal degradation. Here we present ten cryogenic electron microscopy (cryo-EM) structures, revealing the mechanistic basis of individual steps of the CAT tailing cycle covering initiation, decoding, peptidyl transfer, and tRNA translocation. We discovered eIF5A as a crucial eukaryotic RQC factor enabling peptidyl transfer. Moreover, we observed dynamic behavior of RQC factors and tRNAs allowing for processivity of the CAT tailing cycle without additional energy input. Together, these results elucidate key differences as well as common principles between CAT tailing and canonical translation.

PubMed: 36804914
DOI: 10.1016/j.molcel.2023.01.020

Experimental method

ELECTRON MICROSCOPY (2.6 Å)