Clever use of group I permuted intron-exon sequences to obtain circular riboregulators that performs better than their linear counterparts.
For the whole story, read the preprint on @bioRxiv
Engineering a circular riboregulator in Escherichia coli
William Rostain, Shensi Shen, Teresa Cordero, Guillermo Rodrigo, Alfonso Jaramillo
Circular RNAs have recently been shown to be important gene expression regulators in mammalian cells. However, their role in prokaryotes remains elusive. Here, we engineered a synthetic riboregulator that self-splice to produce a circular molecule, exploiting group I permuted intron-exon (PIE) sequences. We demonstrated that the resulting circular riboregulator can activate gene expression, showing increased dynamic range compared to the linear form. We characterized the system with a fluorescent reporter and with an antibiotic resistance marker. Thanks to the increased regulatory activity by higher stability, isolation due to self-splicing, and modularity of PIE, we envisage engineered circular riboregulators in further synthetic biology applications.