Céline Fabret, Emmanuel Giudice, Sophie Chat, Reynald Gillet, Olivier Namy
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引用次数: 0
Abstract
Eukaryotic cells prevent the accumulation of potentially toxic aberrant polypeptides and maintain ribosome availability through surveillance and clearance mechanisms, including the evolutionarily conserved ribosome-associated quality control complex (RQC). RQC pathways have been widely investigated, with the identification of several factors ANKZF1/Vms1p, Ptrh1, and Arb1p involved in release/cleavage of the peptide-tRNA from 60S subunits. We aimed here to identify the genes involved in peptide release from stalled ribosomes. Using a genetic screen, we identified a mutant allele of RQC2 as involved in this process. We present the cryoelectron microscopy (cryo-EM) structure of RQC, which reveals how the F340I mutation affects mutant binding. This altered binding, in turn, disrupts the A-site’s ability to bind the tRNA in the presence of Ltn1. These data account for the limitation of C-terminal alanine and threonine (CAT) tailing by the F340I mutation and suggest a model explaining the role of the Rqc2 protein in peptide release.
期刊介绍:
Structure aims to publish papers of exceptional interest in the field of structural biology. The journal strives to be essential reading for structural biologists, as well as biologists and biochemists that are interested in macromolecular structure and function. Structure strongly encourages the submission of manuscripts that present structural and molecular insights into biological function and mechanism. Other reports that address fundamental questions in structural biology, such as structure-based examinations of protein evolution, folding, and/or design, will also be considered. We will consider the application of any method, experimental or computational, at high or low resolution, to conduct structural investigations, as long as the method is appropriate for the biological, functional, and mechanistic question(s) being addressed. Likewise, reports describing single-molecule analysis of biological mechanisms are welcome.
In general, the editors encourage submission of experimental structural studies that are enriched by an analysis of structure-activity relationships and will not consider studies that solely report structural information unless the structure or analysis is of exceptional and broad interest. Studies reporting only homology models, de novo models, or molecular dynamics simulations are also discouraged unless the models are informed by or validated by novel experimental data; rationalization of a large body of existing experimental evidence and making testable predictions based on a model or simulation is often not considered sufficient.