Science for All | What is RNA origami? 

The Hindu’s weekly Science for All newsletter explains all things Science, without the jargon.

RNA, or ribonucleic acid, is a single stranded nucleic acid akin to DNA that’s present in all cells and necessary for translating the genetic code into proteins. 

RNA origami is an attempt to generate complex human-made RNA-based devices that are stable in cells, interact with other biomolecules, including other RNA and proteins, and enable unique applications, particularly in the context of gene regulation. So far there have been two approaches in RNA origami and both attempt to regulate the production of protein.

In one approach, origami was used to achieve precise control of protein production levels when expressed in bacteria. Self-inhibiting protein expression cassettes were made by installing a strong binding site for the expressed protein in its own gene. Afterwards, RNA origami decorated with the same protein-binding sites was expressed in large excess. In this way, the RNA origami serves as a protein-sponge that sequesters proteins in the cell and allows expression of the self-inhibited protein. This approach helped to regulate several proteins simultaneously and turn on enzymatic pathways for improved product yields. 

In the second approach, RNA origami was combined with CRISPR, a gene editing tool. The RNA origamis were integrated in the small RNAs that guide CRISPR-Cas9 enzyme to target specific sequences in the DNA genome. The RNA origami scaffolds were decorated with protein-binding sites capable of recruiting transcription factors. By targeting the RNA scaffolds to promoter regions, the transcription factors activated gene expression. Researchers have shown that the expression strength can be tuned by the orienting the scaffold and level of transcription factors recruited. These multi-enzyme pathways could be controlled for high-yield production of the anti-cancer drug violacein. 

Neutralising antibody against multiple SARS-CoV-2 variants

Learning from new life forms

Lectures transcreated from English to five Indian languages