Mechanism of co-transcriptional RNA origami. A DNA template is transcribed by RNA polymerase, whereby the RNA folds up into tiles that self-assemble into higher-order RNA origami nanotubes. The folding steps are numbered: the nascent RNA folds first into local secondary structures (stem-loops), followed by the formation of long-distance tertiary structures through internal kissing loops and finally oligomerization via various quaternary interactions (external kissing loops, overhangs and aptamers).
