ABSTRACT
Objective To compare the regulation effects of different activated and inhibitory riboswitches , and to facilitate the precise regulation of gene circuits .Methods A green fluorescent protein amcyan expression vector regulated by different riboswitches (addA, M6, TPP and btuB) was constructed, and the expression level of amcyan under different ligand concentrations was analyzed by RT-qPCR and relative fluorescence intensity , and then compared with the expression level of a vector without any riboswitch .The dynamic control performance was analyzed .Results Under the control of addA and M6 activated riboswitches , the expression of green fluorescent protein increased with ligand concentrations , and addA riboswitch had more dynamic regulatory effect than M 6 riboswitch.However, under the control of TPP and btuB inhibitory riboswitches , the expression of green fluorescence decreased with the increase in ligand concentrations , and the dynamic regulation of btuB riboswitch was slightly greater than that of TPP riboswitch .Conclusion The regulation efficacy of different riboswitches which have the same mechanism varies .Activated riboswitch addA and inhibitory riboswitch btuB with dynamic regulation and control advantages are more suitable for precise metabolism regulation and target gene expression in Escherichia coli.