Reuther, JuliaJuliaReutherSchneider, LukasLukasSchneiderIacovache, IoanIoanIacovachePircher, AndreasAndreasPircherGharib, Walid H.Walid H.GharibZuber, BenoîtBenoîtZuber0000-0001-7725-5579Polacek, NorbertNorbertPolacek0000-0001-5317-39902024-10-052024-10-052021-06-13https://boris-portal.unibe.ch/handle/20.500.12422/56933Ribosome-associated non-coding RNAs (rancRNAs) have been recognized as an emerging class of regulatory molecules capable of fine-tuning translation in all domains of life. RancRNAs are ideally suited for allowing a swift response to changing environments and are therefore considered pivotal during the first wave of stress adaptation. Previously, we identified an mRNA-derived 18 nucleotides long rancRNA (rancRNA_18) in Saccharomyces cerevisiae that rapidly downregulates protein synthesis during hyperosmotic stress. However, the molecular mechanism of action remained enigmatic. Here, we combine biochemical, genetic, transcriptome-wide and structural evidence, thus revealing rancRNA_18 as global translation inhibitor by targeting the E-site region of the large ribosomal subunit. Ribosomes carrying rancRNA_18 possess decreased affinity for A-site tRNA and impaired structural dynamics. Cumulatively, these discoveries reveal the mode of action of a rancRNA involved in modulating protein biosynthesis at a thus far unequalled precision.en500 - Science::570 - Life sciences; biology500 - Science::540 - Chemistry600 - Technology::610 - Medicine & healtharticle10.48350/15701710.1080/15476286.2021.1935573