| Popis: |
Transfer ribonucleic acids (tRNAs) are the key elements in protein biosynthesis. Indeed, these RNAs, charged with a specific amino acid, bind to messenger RNA and transfer their amino acid to the growing peptide chain. In order to fulfill this role, the tRNA has to interact with numerous macromolecular partners such as aminoacyl-tRNA synthetases (enzymes which catalyze binding of the specific amino acid), elongation factors, messenger RNA and different sites on the ribosome. The molecular mechanisms governing these various interactions, largely studied for cytosolic tRNAs, are based on the recognition of the three-dimensional structure of tRNA and on the recognition of signals on the surface of this structure (Soil and RajBhandary 1995). This has been best studied in the aminoacylation reaction, the key reaction of the whole process of protein synthesis (e.g. Saks et al. 1994; McClain 1995; Giege et al. 1998). In particular, it is well established that any perturbation affecting either the structure an/or the recognition signals has the potential to lead to a functional deficiency in these molecules. |
