During the last years, the newly discovered functions of RNA in cells aroused growing interest in cell biology as well as in microbiology and biotechnology. RNA can serve in all kind of cells not only as the long-known messenger from genes to proteins but moreover plays a major role in structural and functional aspects of the translation machinery: The ribosome itself consists of a mixture of proteins and RNA where the main catalytic feature of the ribosome, the peptide bond formation, is even catalyzed by RNA residues. Furthermore ribosomal RNA is also involved in translation initiation, in particular by complementary binding to the messenger RNA. The main task of this project will be the introduction of a controllable self-cleaving RNA element, a so called aptazyme, in the ribosomal RNA scaffold without disturbing its original activity. Not until the addition of a specific ligand, the aptazyme becomes activated and starts to degrade the ribosome which finally leads to a decreased gene expression level. This controllable ribosome should provide a valuable tool for cell biology and the emerging field of Synthetic Biology.
