Structural Patching Fosters Divergence of Mitochondrial Ribosomes
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.
Mitoribosomes synthesize proteins encoded by the mt-genome.
ablation and expansion of mt-rRNA generates metastable regions of mitoribosomes that require patching by pre-existing elements that may confer new functions. The extent and type of modifications that can be made in different species are determined by the structural toolkits available. Fungal mitoribosomes have a structural toolkit that includes mt-rRNA expansion and protein acquisition, whereas metazoans appear to be restricted to only adding existing RNA elements and proteins. 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.