Nuclear magnetic resonance techniques for studying structure and function of ribosomes

The following conclusions can be drawn from the use of NMR techniques for studies of ribosomes: 1. The majority of ribosomal proteins are rigidly fixed within the particles, and the most mobile components in the isolated ribosome are L7/L12 proteins from the large subunit. 2. Interaction of EF-G with ribosomes results in some changes in ribosomal domains, and, particularly, immobilization of L7/L12 proteins takes place. The changes may pertain to the translocation reaction, since complexes with ribosomes, EF-G, and GTP are functional. The results of these studies using 1H NMR show that structural studies with this technique are limited as only a few proteins express their resonances in the 1H NMR spectra (S1, L7/L12). At the same time such studies are not exhaustive, since only the simplest samples were studied (ribosomes, the ribosomal complex with EF-G). Complexes with other ligands (tRNA, EF-Tu) have not yet been studied. It is also possible to enhance the resolution of 1H NMR techniques with the help of deuterated factors, ribosomes, and proteins, and to adapt the use of NMR to other nuclei (e.g., the use of fluorinated labels or incorporation of fluoroamino acids into the proteins). Many other approaches using NMR in biology have still to be explored. Therefore it is hoped that the use of NMR techniques will prove to be very useful in studies of the different functional steps of protein biosynthesis.