Abstract: Disclosed is a method for identifying compounds (lead structures) which specifically bind to (a) desired RNA target motif and can inhibit or eliminate the function thereof or (b) suppress a compound associated with a desired RNA target motif and can thereby inhibit or eliminate the function thereof. The inventive method is based on the attachment of a ligand (=a compound to be identified) to a RNA target motif which is coupled to a modified ribozyme so that the ribozyme is transformed into an active or inactive conformation resulting in the cleaving of a signal-giving ribozyme substrate. The identified compounds enabling modification of the cellular function of the RNA target motifs enable specific medicaments to be produced. The invention also relates to a polynucleotide comprising a hammerhead ribozyme and an aptamer for a target molecule.