An Unexpectedly Complex Mitoribosome in Andalucia godoyi, a Protist with the Most Bacteria-like Mitochondrial Genome.

Autor:	Valach M; Department of Biochemistry and Molecular Medicine, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Quebec, Canada., Gonzalez Alcazar JA; Department of Biochemistry and Molecular Medicine, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Quebec, Canada., Sarrasin M; Department of Biochemistry and Molecular Medicine, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Quebec, Canada., Lang BF; Department of Biochemistry and Molecular Medicine, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Quebec, Canada., Gray MW; Department of Biochemistry and Molecular Biology, Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada., Burger G; Department of Biochemistry and Molecular Medicine, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Quebec, Canada.
Jazyk:	angličtina
Zdroj:	Molecular biology and evolution [Mol Biol Evol] 2021 Mar 09; Vol. 38 (3), pp. 788-804.
DOI:	10.1093/molbev/msaa223
Abstrakt:	The mitoribosome, as known from studies in model organisms, deviates considerably from its ancestor, the bacterial ribosome. Deviations include substantial reduction of the mitochondrial ribosomal RNA (mt-rRNA) structure and acquisition of numerous mitochondrion-specific (M) mitoribosomal proteins (mtRPs). A broadly accepted view assumes that M-mtRPs compensate for structural destabilization of mt-rRNA resulting from its evolutionary remodeling. Since most experimental information on mitoribosome makeup comes from eukaryotes having derived mitochondrial genomes and mt-rRNAs, we tested this assumption by investigating the mitochondrial translation machinery of jakobids, a lineage of unicellular protists with the most bacteria-like mitochondrial genomes. We report here proteomics analyses of the Andalucia godoyi small mitoribosomal subunit and in silico transcriptomic and comparative genome analyses of four additional jakobids. Jakobids have mt-rRNA structures that minimally differ from their bacterial counterparts. Yet, with at least 31 small subunit and 44 large subunit mtRPs, the mitoriboproteome of Andalucia is essentially as complex as that in animals or fungi. Furthermore, the relatively high conservation of jakobid sequences has helped to clarify the identity of several mtRPs, previously considered to be lineage-specific, as divergent homologs of conserved M-mtRPs, notably mS22 and mL61. The coexistence of bacteria-like mt-rRNAs and a complex mitoriboproteome refutes the view that M-mtRPs were ancestrally recruited to stabilize deviations of mt-rRNA structural elements. We postulate instead that the numerous M-mtRPs acquired in the last eukaryotic common ancestor allowed mt-rRNAs to pursue a broad range of evolutionary trajectories across lineages: from dramatic reduction to acquisition of novel elements to structural conservatism. (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)
Databáze:	MEDLINE
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