A regulatable gene expression construct comprising a nucleic acid molecule encoding an RNA comprising a riboswitch operably linked to a sequence, wherein the riboswitch comprises an aptamer domain and an expression platform domain, wherein the riboswitch regulates expression of the sequence via dynamic interplay between the aptamer domain and the expression platform domain resulting in allosteric control of expression of the sequence, wherein the riboswitch and sequence are heterologous, wherein the sequence does not encode β-galactosidase wherein the riboswitch comprises the consensus structure of FIG. 11A, 11B, 11C, 11D, 11E, 11F, 11G, 14A, 19A, 24A or 30A.