Hibernation-Promoting Factor Sequesters Staphylococcus aureus Ribosomes to Antagonize RNase R-Mediated Nucleolytic Degradation
Anna Lipońska, Mee‐Ngan F. Yap
Abstract
Ribosome hibernation is pivotal for the rapid recovery of translation after quiescence in both bacteria and eukaryotes. Ribosome hibernation factors sterically occlude the entry of mRNA and tRNA and are thought to primarily maintain ribosomes in a translation-repressive state, thereby providing a pool of readily recyclable 70S or 80S complexes upon dissociation of the hibernation factors. Ribosomes in Staphylococcus aureus cells lacking the sole hibernation factor HPF are extremely unstable. Here, we show that HPF binding inhibits ribosome degradation by the evolutionarily conserved exoribonuclease RNase R. The data not only uncover a direct protective role of HPF in ribosome stability but also reinforce the versatility of RNase R in RNA processing, decay, and ribosome quality control.