Low-frequency Raman scattering of transfer and ribosomal RNA

DNA and RNA are essential for the life of all organisms, as they support the storage and transfer of hereditary information and its use in protein construction. In addition, some noncoding RNAs are parts of various molecular machines, for instance, ribosomes. The tertiary structures of DNA and RNA are of paramount importance for their normal functioning in replication, transcription, and translation. Information on these structures can be obtained from Raman spectra in the low-frequency (LF) range (below 200 cm$^{-1}$). This is the first report on such spectra for two noncoding RNAs, transfer and ribosomal (the latter within ribosomes) and their comparison with the DNA spectrum. It has been found that the two RNA spectra are very similar in the range below 100 cm$^{-1}$, but they are significantly different in the range of 100–200 cm$^{-1}$ after subtracting the characteristic broadband signal. In addition, the LF Raman scattering intensity of RNA is notably lower than that of DNA. This difference, additionally confirmed by a molecular dynamics simulation of transfer RNA and DNA, is related to the greater ordering of RNA than DNA owing to the stronger interaction between segments of biomolecules. Thus, the study of LF Raman spectra of nucleic acids may provide information for understanding their state, determining the course of key intracellular processes.