摘要：rNAs of different shapes and sizes,natural or synthetic,can regulate gene expression in prokaryotes and *** rNAs have recently appeared to be more widespread than previously thought,but their role in prokaryotes remains ***,by inserting a riboregulatory sequence within a group I permuted intron-exon ribozyme,we created a small noncoding rNA that self-splices to produce a circular riboregulator in Escherichia *** showed that the resulting riboregulator can trans-activate gene expression by interacting with a cis-repressed messenger *** characterized the system with a fluorescent reporter and with an antibiotic resistance marker,and we modeled this novel posttranscriptional *** first reported example of a circular rNA regulating gene expression in *** adds to an increasing repertoire of rNA synthetic biology parts,and it highlights that topological molecules can play a role in the case of prokaryotic regulation.