Structural basis for clearing of ribosome collisions by the RQT complex.
Nat Commun
; 14(1): 921, 2023 02 17.
Article
em En
| MEDLINE
| ID: mdl-36801861
ABSTRACT
Translation 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.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ribossomos
/
DNA Helicases
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article