Rapid knockdown of target genes using synthetic small regulatory RNAs system and its application on metabolic engineering: Tyrosine and cadaverine production

Abstract

Small regulatory RNAs (sRNAs) act on gene expression system after transcription inbacteria. We replaced MicC, which is a sRNA in Escherichia coli with translation startsequence of target genes. The synthetic sRNA system was successfully repressed thegene expression of DsRed2. This system was used for enhancing the tyrosine andcadaverine production in this study. 14 different strains were developed whichrespectively harboring one or set of the synthetic sRNAs targeting ppc, tyrR, csrA, andpgi. After screening, we selected a strain producing 2 g/L tyrosine. To increasingcadaverine production rate, we additionally screened 130 synthetic sRNAs library andas a result, murE repression was found to increase cadaverine productivity up to 55% ofbase strain. [This work was supported by the Technology Development Program toSolve Climate Changes on Systems Metabolic Engineering for Biorefineries; the Intelligent Synthetic Biology Center through the GlobalFrontier Project of the Ministry of Education, Science and Technology(MEST) through the National Research Foundation of Korea]