RNA thermometers are a class of mRNAs that change their translation initiation rates with temperature. The mechanisms by which these molecules act is fairly simple. At low temperatures, the ribosome-binding site (RBS) is sequestered in a hair-pin structure preventing ribosomes from binding to the mRNA effectively. As temperature increases, these structures melt allowing ribosomes to initiate translation on them. These molecules are typically associated with a special class of sigma-factor genes in bacteria that regulate heat-shock and other chaperone genes. However, little is known about how widespread these class of molecules are. We studied the melting of RNAs with temperature by computationally sampling the distribution of the RNA structures at various temperatures using the RNA folding software Vienna. To our surprise, we found that while known RNA thermometers had a higher melting rate with temperature than non-thermometers, these higher rates weren't significant. This suggests that RNA thermometers are perhaps not a special class of structurally distinct RNA molecules.


Is thermosensing property of RNA thermometers unique? Shah & Gilchrist PLOS ONE 2010