The RNA thermometer motif ROSE-G regulates ABC transporter gene expression in bacteria

RNA thermometers are temperature-sensing non-coding RNAs that regulate the expression of downstream genes. We previously reported that a well-characterized RNA thermometer, the ROSE-like element (repression of heat shock gene expression), is broadly distributed upstream of ATP-binding cassette (ABC) transporter genes in bacteria. ABC transporters are a superfamily of transmembrane proteins that harness ATP hydrolysis to facilitate the export and import of substrates across cellular membranes. Through structure-guided bioinformatics, we have now discovered a novel RNA motif, ROSE-G, that is closely related to the canonical ROSE-like motif. The newly identified ROSE-G motif is also widespread upstream of ABC transporter genes across diverse bacterial species. Structure probing, biochemistry, and cellular assays collectively indicate that this newly identified motif functions as an RNA thermometer. This study expands the known classes of RNA thermometers and further underscores the importance of RNA thermometers in the post-transcriptional regulation of ABC transporters in bacteria.