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bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.09.11.612461
preprint
1
Article
The RNA helicase HrpA rescues collided ribosomes in E. coli
Campbell Annabelle
Esser Hanna F.
Burroughs A. Maxwell
Berninghausen Otto
Aravind L.
Becker Thomas
Green Rachel
Beckmann Roland
Buskirk Allen R.
11 9 2024
2024.09.11.612461https://creativecommons.org/licenses/by-nc-nd/4.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which allows reusers to copy and distribute the material in any medium or format in unadapted form only, for noncommercial purposes only, and only so long as attribution is given to the creator.
http://biorxiv.org/lookup/doi/10.1101/2024.09.11.612461
nihpp-2024.09.11.612461.pdf
Abstract

Although many antibiotics inhibit bacterial ribosomes, loss of known factors that rescue stalled ribosomes does not lead to robust antibiotic sensitivity in E. coli , suggesting the existence of additional mechanisms. Here, we show that the RNA helicase HrpA rescues stalled ribosomes in E. coli. Acting selectively on ribosomes that have collided, HrpA uses ATP hydrolysis to split stalled ribosomes into subunits. Cryo-EM structures reveal how HrpA simultaneously binds to two collided ribosomes, explaining its selectivity, and how its helicase module engages downstream mRNA, such that by exerting a pulling force on the mRNA, it would destabilize the stalled ribosome. These studies show that ribosome splitting is a conserved mechanism that allows proteobacteria to tolerate ribosome-targeting antibiotics.
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