Download MendeleyElongational stalling activates mitoribosome-associated quality control.
Desai, N., Yang, H., Chandrasekaran, V., Kazi, R., Minczuk, M., Ramakrishnan, V.(2020) Science 370: 1105-1110
- PubMed: 33243891
- DOI: https://doi.org/10.1126/science.abc7782
- Primary Citation of Related Structures:
7A5F, 7A5G, 7A5H, 7A5I, 7A5J, 7A5K - PubMed Abstract:
The human mitochondrial ribosome (mitoribosome) and associated proteins regulate the synthesis of 13 essential subunits of the oxidative phosphorylation complexes. We report the discovery of a mitoribosome-associated quality control pathway that responds to interruptions during elongation, and we present structures at 3.1- to 3.3-angstrom resolution of mitoribosomal large subunits trapped during ribosome rescue. Release factor homolog C12orf65 (mtRF-R) and RNA binding protein C6orf203 (MTRES1) eject the nascent chain and peptidyl transfer RNA (tRNA), respectively, from stalled ribosomes. Recruitment of mitoribosome biogenesis factors to these quality control intermediates suggests additional roles for these factors during mitoribosome rescue. We also report related cryo-electron microscopy structures (3.7 to 4.4 angstrom resolution) of elongating mitoribosomes bound to tRNAs, nascent polypeptides, the guanosine triphosphatase elongation factors mtEF-Tu and mtEF-G1, and the Oxa1L translocase.
Organizational Affiliation:
MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
