title: Engineered riboswitches control gene expression by small molecules.
abstract: We have developed conditional gene expression systems based on engineered small-molecule-binding riboswitches. Tetracycline-dependent regulation can be imposed on an mRNA in yeast by inserting an aptamer in its 5'-untranslated region. Biochemical and genetic analyses determined that binding of the ligand tetracycline leads to a pseudoknot-like linkage within the aptamer structure, thereby inhibiting the initial steps of translation. A second translational control element was designed by combining a theophylline aptamer with a communication module for which a 1 nt slipping mechanism had been proposed. This structural element was inserted close to the bacterial ribosomal binding site at a position just interfering with translation in the non-ligand-bound form. Addition of the ligand then shifts the inhibitory element to a distance that permits efficient translation.
authors.affiliation: Lehrstuhl für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, D-91058 Erlangen, Germany. bsuess@biologie.uni-erlangen.de
authors.forename: B
authors.initials: B
authors.lastname: Suess
mesh_terms: D001483:Base Sequence; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000235:genetics*; D014176:Protein Biosynthesis / Q000187:drug effects / Q000235:genetics; D012313:RNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D013752:Tetracycline / Q000494:pharmacology*; D013806:Theophylline / Q000494:pharmacology
chemical_list: D012313:RNA; D013806:Theophylline; D013752:Tetracycline