A metastable rRNA junction essential for bacterial 30S biogenesis
In: Nucleic Acids Research, Jg. 46 (2018-02-23), S. 5182-5194
Online
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Zugriff:
Tertiary sequence motifs encode interactions between RNA helices that create the three-dimensional structures of ribosomal subunits. A Right Angle motif at the junction between 16S helices 5 and 6 (J5/6) is universally conserved amongst small subunit rRNAs and forms a stable right angle in minimal RNAs. J5/6 does not form a right angle in the mature ribosome, suggesting that this motif encodes a metastable structure needed for ribosome biogenesis. In this study, J5/6 mutations block 30S ribosome assembly and 16S maturation in Escherichia coli. Folding assays and in-cell X-ray footprinting showed that J5/6 mutations favor an assembly intermediate of the 16S 5′ domain and prevent formation of the central pseudoknot. Quantitative mass spectrometry revealed that mutant pre-30S ribosomes lack protein uS12 and are depleted in proteins uS5 and uS2. Together, these results show that impaired folding of the J5/6 right angle prevents the establishment of inter-domain interactions, resulting in global collapse of the 30S structure observed in electron micrographs of mutant pre-30S ribosomes. We propose that the J5/6 motif is part of a spine of RNA helices that switch conformation at distinct stages of assembly, linking peripheral domains with the 30S active site to ensure the integrity of 30S biogenesis.
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A metastable rRNA junction essential for bacterial 30S biogenesis
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Autor/in / Beteiligte Person: | Woodson, Sarah A. ; Rappé, Mollie C. ; Zhuang, Zhuoyun ; Limbach, Patrick A. ; Addepalli, Balasubrahmanyam ; Indra Mani Sharma ; Grabow, Wade W. ; Jaeger, Luc ; Abeysirigunawardena, Sanjaya |
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Zeitschrift: | Nucleic Acids Research, Jg. 46 (2018-02-23), S. 5182-5194 |
Veröffentlichung: | Oxford University Press (OUP), 2018 |
Medientyp: | unknown |
ISSN: | 1362-4962 (print) ; 0305-1048 (print) |
DOI: | 10.1093/nar/gky120 |
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