Toxic Small RNA

In molecular biology, Toxic Small RNA (tsRNA) is a small non-coding RNA found exclusively in Betaproteobacteria. Its function is unknown, but based on sequence and structure conservation, it is predicted to target the ribosomal binding site (RBS) area in the 5’ UTR of various genes. It was found that expression of tsRNAs within E. coli inhibits E. coli growth, in a mechanism which is still unknown (and hence the name Toxic Small RNA). Several paralogous loci may encode similar (but not identical) tsRNAs in each coding genome. Experiments with four species of the Burkholderia lineage showed conserved and constitutive expression of tsRNAs in logarithmic growth phases.