Fig. 1: Design, folding, and cellular assembly of co-transcriptionally folded ssRNA tiles.
From: Designer RNA nanostructures co-transcribed and self-assembled inside human cell nuclei
A Schematic design of a ssRNA tile, Design 3 (D3). ‘RNA KLs’ refers to RNA kissing loop motifs, and ‘RNA PC’ denotes RNA paranemic cohesion. The 3D model shows the composition and folded conformation of the ssRNA tile. B Routing map of the co-transcriptional folding of D3. The blue line indicates the first half of the D3 sequence, and the red line indicates the second half. C Schematic of the co-transcriptional folding and assembly of Design 4 (D4) tile in the human cell nucleus. Step 1: RNA polymerase binds the DNA template and begins synthesizing the first paranemic cohesion domain, leaving an open stem-loop structure. Step 2: The first half of D4 is completed, forming half of the RNA PC domain and one branched arm containing an RNA branch kissing loop (BKL). Step 3: The second half of the RNA PC domain is synthesized and pairs with the first half, forming a stabilized RNA PC configuration. Step 4: The second branched arm with an RNA BKL is transcribed, completing the folding of D4. Tile monomers subsequently assemble into lattices within the nucleus via RNA kissing loop interactions.
