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Hibernation factors directly block ribonucleases from entering the ribosome in response to starvation.

ABSTRACT: Ribosome hibernation is a universal translation stress response found in bacteria as well as plant plastids. The term was coined almost two decades ago and despite recent insights including detailed cryo-EM structures, the physiological role and underlying molecular mechanism of ribosome hibernation has remained unclear. Here, we demonstrate that Escherichia coli hibernation factors RMF, HPF and RaiA (HFs) concurrently confer ribosome hibernation. In response to carbon starvation and resulting growth arrest, we observe that HFs protect ribosomes at the initial stage of starvation. Consistently, a deletion mutant lacking all three factors (ΔHF) is severely inhibited in regrowth from starvation. ΔHF cells increasingly accumulate 70S ribosomes harbouring fragmented rRNA, while rRNA in wild-type 100S dimers is intact. RNA fragmentation is observed to specifically occur at HF-associated sites in 16S rRNA of assembled 70S ribosomes. Surprisingly, degradation of the 16S rRNA 3'-end is decreased in cells lacking conserved endoribonuclease YbeY and exoribonuclease RNase R suggesting that HFs directly block these ribonucleases from accessing target sites in the ribosome.

SUBMITTER: Prossliner T

PROVIDER: S-EPMC7913689 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature

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Hibernation factors directly block ribonucleases from entering the ribosome in response to starvation.

Prossliner Thomas T Gerdes Kenn K Sørensen Michael Askvad MA Sørensen Michael Askvad MA Winther Kristoffer Skovbo KS

Nucleic acids research 20210201 4

Ribosome hibernation is a universal translation stress response found in bacteria as well as plant plastids. The term was coined almost two decades ago and despite recent insights including detailed cryo-EM structures, the physiological role and underlying molecular mechanism of ribosome hibernation has remained unclear. Here, we demonstrate that Escherichia coli hibernation factors RMF, HPF and RaiA (HFs) concurrently confer ribosome hibernation. In response to carbon starvation and resulting g ...[more]

PMID: 33503254

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Hibernation factors directly block ribonucleases from entering the ribosome in response to starvation.

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Hibernation factors directly block ribonucleases from entering the ribosome in response to starvation.

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