7zs5
From Proteopedia
Structure of 60S ribosomal subunit from S. cerevisiae with eIF6 and tRNA
Structural highlights
FunctionIF6_YEAST Binds to the 60S ribosomal subunit and prevents its association with the 40S ribosomal subunit to form the 80S initiation complex in the cytoplasm. Is also involved in ribosome biogenesis. Associates with pre-60S subunits in the nucleus and is involved in its nuclear export. Cytoplasmic release of TIF6 from 60S subunits and nuclear relocalization is promoted by the GTPase RIA1/EFL1 and by SDO1. Also required for pre-rRNA processing.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedTranslation of aberrant messenger RNAs can cause stalling of ribosomes resulting in ribosomal collisions. Collided ribosomes are specifically recognized to initiate stress responses and quality control pathways. Ribosome-associated quality control facilitates the degradation of incomplete translation products and requires dissociation of the stalled ribosomes. A central event is therefore the splitting of collided ribosomes by the ribosome quality control trigger complex, RQT, by an unknown mechanism. Here we show that RQT requires accessible mRNA and the presence of a neighboring ribosome. Cryogenic electron microscopy of RQT-ribosome complexes reveals that RQT engages the 40S subunit of the lead ribosome and can switch between two conformations. We propose that the Ski2-like helicase 1 (Slh1) subunit of RQT applies a pulling force on the mRNA, causing destabilizing conformational changes of the small ribosomal subunit, ultimately resulting in subunit dissociation. Our findings provide conceptual framework for a helicase-driven ribosomal splitting mechanism. Structural basis for clearing of ribosome collisions by the RQT complex.,Best K, Ikeuchi K, Kater L, Best D, Musial J, Matsuo Y, Berninghausen O, Becker T, Inada T, Beckmann R Nat Commun. 2023 Feb 17;14(1):921. doi: 10.1038/s41467-023-36230-8. PMID:36801861[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Large Structures | Saccharomyces cerevisiae | Becker T | Beckmann R | Berninghausen O | Best DM | Best KM | Ikeuchi K | Inada T | Kater L | Matsuo Y | Musial J
