Biological complexity: structure of a mitochondrial ribosome (Introduction)

by David Turell , Tuesday, February 16, 2021, 18:31 (1376 days ago) @ David Turell

Involves 22 associated factors:

https://phys.org/news/2021-02-glimpse-formation-mitoribosome.html

"SciLifeLab Fellow Alexey Amunts and his team together with researchers from the Czech Academy of Sciences report an assembly intermediate of the ribosome in mitochondria. It reveals 22 associated factors that cooperatively organize the biogenesis process.

"The mitochondrial ribosome is an intricate machine that translates the organellar genome into functional proteins. The formation of the mitochondrial ribosome is a hierarchical process involving dozens of different components.

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"The resulting structure revealed that the assembly factors form a network that spans a distance of 18 nanometres shielding the sensitive ribosomal core that is made of less-stable nucleic acids. The network is designed to connect all the functional regions on the mitoribosomal large subunit for their correlated maturation.

"A phylogenetic analysis further showed that most of the newly identified assembly factors also exist in human, and therefore the derived characteristics represent general principles. However, an unexpected finding is that some of those factors appeared to loose their activity. Despite being deactivated, they still contribute as structural mediators for a stabilization of the functionally active partners on the mitoribosomal core. The preservation of the deactivated factors implies a mechanism of the evolutionary conservation of the sequential assembly."

Comment: Such purposeful complexity is not a result of chance organization