Snapshots of native pre-50S ribosomes reveal a biogenesis factor network and evolutionary specialization

• Published in: Molecular cell 2021-03, Vol.81 (6), p.1200-1215.e9
• Main Authors: Nikolay, Rainer, Hilal, Tarek, Schmidt, Sabine, Qin, Bo, Schwefel, David, Vieira-Vieira, Carlos H., Mielke, Thorsten, Bürger, Jörg, Loerke, Justus, Amikura, Kazuaki, Flügel, Timo, Ueda, Takuya, Selbach, Matthias, Deuerling, Elke, Spahn, Christian M.T.
• Format: Article
• Language: English
• Subjects: 50S subunit; cryo-electron microscopy; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Evolution, Molecular; Genetic Loci; Hydro-Lyases - chemistry; Hydro-Lyases - genetics; Hydro-Lyases - metabolism; Monomeric GTP-Binding Proteins - chemistry; Monomeric GTP-Binding Proteins - genetics; Monomeric GTP-Binding Proteins - metabolism; ObgE; ribosome; ribosome assembly; ribosome biogenesis; Ribosome Subunits, Large, Bacterial - chemistry; Ribosome Subunits, Large, Bacterial - genetics; Ribosome Subunits, Large, Bacterial - metabolism; RluD; RsfS; structure; YjgA
• ISSN: 1097-2765; 1097-4164
• DOI: 10.1016/j.molcel.2021.02.006

Ribosome biogenesis is a fundamental multi-step cellular process that culminates in the formation of ribosomal subunits, whose production and modification are regulated by numerous biogenesis factors. In this study, we analyze physiologic prokaryotic ribosome biogenesis by isolating bona fide pre-50S subunits from an Escherichia coli strain with the biogenesis factor ObgE, affinity tagged at its native gene locus. Our integrative structural approach reveals a network of interacting biogenesis factors consisting of YjgA, RluD, RsfS, and ObgE on the immature pre-50S subunit. In addition, our study provides mechanistic insight into how the GTPase ObgE, in concert with other biogenesis factors, facilitates the maturation of the 50S functional core and reveals both conserved and divergent evolutionary features of ribosome biogenesis between prokaryotes and eukaryotes. [Display omitted] •Authentic bona fide bacterial pre-50S precursor•Network of interacting biogenesis factors comprising YjgA, RluD, RsfS, and ObgE•ObgE contributes to late assembly by orchestrating distinct maturation events•Simultaneous presence of uL16 and bL36 triggers ObgE’s GTPase activity Nikolay et al. present cryo-EM reconstructions of authentic bacterial on-pathway pre-50S ribosomal precursor particles exhibiting a collaborative network of biogenesis factors. This is reminiscent of biogenesis factor networks found in ribosomal precursors of eukaryotic nuclei, cytosol, and organelles, indicating a conserved evolutionary principle.