earticle

영어

In recent years, studies in synthetic biology have demonstrated that noncoding RNA elements play important roles in controlling gene regulatory network1-2. We have constructed intragenic synthetic riboswitches from which gene expression is controlled by well-defined molecular interaction between a ligand and an aptamer sequence 3-4 incoporated in the riboswitch. The translational regulatory riboswitch is designed to display specific binding affinity toward theophylline, leading to lignad-mediated genetic regulation. The riboswitch displays a dose-dependent decrease in translational efficiency of a reporter gene upon exposing to theophylline. Structurally similar derivatives of theophylline, such as caffeine and xanthine, are unable to switch the riboswitch, illustrating exquisite target specificity. The addition of theophylline is seemingly to interfere with translational initiation by blocking formation of an initiation
complex. We introduced various mutations to aptamer sequence in the riboswitches and each riboswitch shows different expression levels of the reporter gene owing to formation of secondary structure. The introduction of mutation affects mRNA secondary structure formation and shows different basal expression and sensitivity of the riboswitch. The translational regulatory riboswitch may be promising for biosensor and in vivo bioimaging system.
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