Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Mechanism of mitoribosomal small subunit biogenesis and preinitiation


Atanassov,  I.
Proteomics, Core Facilities, Max Planck Institute for Biology of Ageing, Max Planck Society;


Rorbach,  J.
Rorbach – Mitochondrial Gene Expression, External and Associated Groups, Max Planck Institute for Biology of Ageing, Max Planck Society;

External Resource
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Itoh, Y., Khawaja, A., Laptev, I., Cipullo, M., Atanassov, I., Sergiev, P., et al. (2022). Mechanism of mitoribosomal small subunit biogenesis and preinitiation. Nature, 606(7914), 603-608. doi:10.1038/s41586-022-04795-x.

Cite as: https://hdl.handle.net/21.11116/0000-000B-B72C-6
Mitoribosomes are essential for the synthesis and maintenance of bioenergetic proteins. Here we use cryo-electron microscopy to determine a series of the small mitoribosomal subunit (SSU) intermediates in complex with auxiliary factors, revealing a sequential assembly mechanism. The methyltransferase TFB1M binds to partially unfolded rRNA h45 that is promoted by RBFA, while the mRNA channel is blocked. This enables binding of METTL15 that promotes further rRNA maturation and a large conformational change of RBFA. The new conformation allows initiation factor mtIF3 to already occupy the subunit interface during the assembly. Finally, the mitochondria-specific ribosomal protein mS37 (ref. (1)) outcompetes RBFA to complete the assembly with the SSU-mS37-mtIF3 complex(2) that proceeds towards mtIF2 binding and translation initiation. Our results explain how the action of step-specific factors modulate the dynamic assembly of the SSU, and adaptation of a unique protein, mS37, links the assembly to initiation to establish the catalytic human mitoribosome.