Journal Article

Principles of mitoribosomal small subunit assembly in eukaryotes

Klinge, Sebastian, Harper, Nathan J., Burnside, Chloe

2023

Overview

Mitochondrial ribosomes (mitoribosomes) synthesize proteins encoded within the mitochondrial genome that are assembled into oxidative phosphorylation complexes. Thus, mitoribosome biogenesis is essential for ATP production and cellular metabolism 1 . Here we used cryo-electron microscopy to determine nine structures of native yeast and human mitoribosomal small subunit assembly intermediates, illuminating the mechanistic basis for how GTPases are used to control early steps of decoding centre formation, how initial rRNA folding and processing events are mediated, and how mitoribosomal proteins have active roles during assembly. Furthermore, this series of intermediates from two species with divergent mitoribosomal architecture uncovers both conserved principles and species-specific adaptations that govern the maturation of mitoribosomal small subunits in eukaryotes. By revealing the dynamic interplay between assembly factors, mitoribosomal proteins and rRNA that are required to generate functional subunits, our structural analysis provides a vignette for how molecular complexity and diversity can evolve in large ribonucleoprotein assemblies. The structures of both human and yeast mitochondrial ribosomal small subunits undergoing assembly are uncovered.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 101/28 / 101/58 / 13/109 / 13/31 / 14 / 38 / 45/77 / 631/45/500 / 631/535/1258/1259 / Adaptation / Assembly / Binding sites / Biosynthesis / Cellular manufacture / Cellular structure / Cryoelectron Microscopy / Divergence / Electron microscopy / Eukaryotes / Fungal Proteins - chemistry / Fungal Proteins - metabolism / Fungal Proteins - ultrastructure / Genomes / GTP Phosphohydrolases / Humanities and Social Sciences / Humans / Intermediates / Microscopy / Mitochondria / Mitochondrial Proteins - chemistry / Mitochondrial Proteins - metabolism / Mitochondrial Proteins - ultrastructure / Mitochondrial Ribosomes - chemistry / Mitochondrial Ribosomes - metabolism / Mitochondrial Ribosomes - ultrastructure / multidisciplinary / Oxidative phosphorylation / Phosphorylation / Principles / Proteins / Ribonucleoproteins - chemistry / Ribonucleoproteins - metabolism / Ribonucleoproteins - ultrastructure / Ribosomal Proteins - chemistry / Ribosomal Proteins - metabolism / Ribosomal Proteins - ultrastructure / Ribosome Subunits, Small - chemistry / Ribosome Subunits, Small - metabolism / Ribosome Subunits, Small - ultrastructure / Ribosomes / RNA processing / RNA, Ribosomal / rRNA / Saccharomyces cerevisiae - cytology / Saccharomyces cerevisiae - metabolism / Science / Science (multidisciplinary) / Structural analysis / Structure-function relationships / Yeast