Structural Patching Fosters Divergence of Mitochondrial Ribosomes

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Structural Patching Fosters Divergence of Mitochondrial Ribosomes

Anton S Petrov, Elizabeth C Wood, Chad R Bernier, Ashlyn M Norris, Alan Brown, A Amunts
Molecular Biology and Evolution, msy221
DOI: 10.1093/molbev/msy221

Mitochondrial ribosomes (mitoribosomes) are essential components of all mitochondria that synthesize proteins encoded by the mitochondrial genome. Unlike other ribosomes, mitoribosomes are highly variable across species. The basis for this diversity is not known.

since the toolkits of elements utilized for structural patching differ between mitochondria of different species, it fosters the growing divergence of mitoribosomes.

Mitochondria are organelles that perform multiple functions within eukaryotic cells including the production of chemical energy. They contain their own mitochondrial genome (mt-genome) and translational machinery.

The origin of non-proteobacterial components as well as the complete history of mitochondrial evolution remain a subject of ongoing studies

Despite the proposed common ancestry, mitoribosomes are morphologically diverse and vary in protein and mt-rRNA content in different species

It has recently become apparent that mitoribosomes have undergone substantial changes within a relatively short evolutionary period in response to a host environment and subsequent diversification of the eukaryotic species

mitoribosomes evolved, and gained new functions, through a “structural patching” of the archetypical ribosome driven by destabilizing changes in mt-rRNA.

it is likely that the more diverse taxa have lineage-specific proteins that are yet to be
identified.

the mitoribosome is a molecular symbiont with a complex evolutionary history.

Further complexity likely comes from constructive neutral evolution, in which structural features become fixed into the mitoribosome through subsequent co-dependent mutations without the apparent evolution of novel functions

Additional structural and phylogenetic analyses will be required to track the specific details of early evolutionary changes within mitoribosomes of bikont species.

The variable extent and rate of changes to the mt-genome and the different toolkits available in different species are responsible for promoting mitoribosomal diversity.

Lots of highly persuasive arguments   🙂