A new family of bacterial ribosome hibernation factors.
Nature
; 626(8001): 1125-1132, 2024 Feb.
Article
en En
| MEDLINE
| ID: mdl-38355796
ABSTRACT
To conserve energy during starvation and stress, many organisms use hibernation factor proteins to inhibit protein synthesis and protect their ribosomes from damage1,2. In bacteria, two families of hibernation factors have been described, but the low conservation of these proteins and the huge diversity of species, habitats and environmental stressors have confounded their discovery3-6. Here, by combining cryogenic electron microscopy, genetics and biochemistry, we identify Balon, a new hibernation factor in the cold-adapted bacterium Psychrobacter urativorans. We show that Balon is a distant homologue of the archaeo-eukaryotic translation factor aeRF1 and is found in 20% of representative bacteria. During cold shock or stationary phase, Balon occupies the ribosomal A site in both vacant and actively translating ribosomes in complex with EF-Tu, highlighting an unexpected role for EF-Tu in the cellular stress response. Unlike typical A-site substrates, Balon binds to ribosomes in an mRNA-independent manner, initiating a new mode of ribosome hibernation that can commence while ribosomes are still engaged in protein synthesis. Our work suggests that Balon-EF-Tu-regulated ribosome hibernation is a ubiquitous bacterial stress-response mechanism, and we demonstrate that putative Balon homologues in Mycobacteria bind to ribosomes in a similar fashion. This finding calls for a revision of the current model of ribosome hibernation inferred from common model organisms and holds numerous implications for how we understand and study ribosome hibernation.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteínas Ribosómicas
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Ribosomas
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Proteínas Bacterianas
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Biosíntesis de Proteínas
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Factores de Terminación de Péptidos
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Psychrobacter
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Respuesta al Choque por Frío
Tipo de estudio:
Prognostic_studies
Idioma:
En
Año:
2024
Tipo del documento:
Article