Zhou, Li-BangLi-BangZhouZeng, An-PingAn-PingZeng2020-06-162020-06-162015-09-01ACS Synthetic Biology 12 (4): 1335-1340 (2015-12-18)http://hdl.handle.net/11420/6326Riboswitches are natural RNA elements that regulate gene expression by binding a ligand. Here, we demonstrate the possibility of altering a natural lysine-OFF riboswitch from Eschericia coli (ECRS) to a synthetic lysine-ON riboswitch and using it for metabolic control. To this end, a lysine-ON riboswitch library was constructed using tetA-based dual genetic selection. After screening the library, the functionality of the selected lysine-ON riboswitches was examined using a report gene, lacZ. Selected lysine-ON riboswitches were introduced into the lysE gene (encoding a lysine transport protein) of Corynebacterium glutamicum and used to achieve dynamic control of lysine transport in a recombinant lysine-producing strain, C. glutamicum LPECRS, which bears a deregulated aspartokinase and a lysine-OFF riboswitch for dynamic control of the enzyme citrate synthase. Batch fermentation results of the strains showed that the C. glutamicum LPECRS strain with an additional lysine-ON riboswitch for the control of lysE achieved a 21% increase in the yield of lysine compared to that of the C. glutamicum LPECRS strain and even a 89% increase in yield compared to that of the strain with deregulated aspartokinase. This work provides a useful approach to generate lysine-ON riboswitches for C. glutamicum metabolic engineering and demonstrates for the first time a synergetic effect of lysine-ON and -OFF riboswitches for improving lysine production in this industrially important microorganism. The approach can be used to dynamically control other genes and can be applied to other microorganisms.en2161-506320151213351340ACSCorynebacterium glutamicumlysine productionmetabolic controlsynthetic lysine-ON riboswitchtetA dual genetic selectionBiowissenschaften, BiologieTechnikJournal Article10.1021/acssynbio.5b00075Other