Note4Students

From UPSC perspective, the following things are important :

Prelims level: RNA Origami

Mains level: Not Much

rna

This newscard is an excerpt of the original article published in The Hindu.

Note: It appears to be too much biological. And suddenly out of our ease of understanding.

What is Ribo Nucleic Acid (RNA)?

RNA is an important biological macromolecule that is present in all biological cells.
It is principally involved in the synthesis of proteins, carrying the messenger instructions from DNA, which itself contains the genetic instructions required for the development and maintenance of life.
In some viruses, RNA, rather than DNA, carries genetic information.
The type of RNA dictates the function that this molecule will have within the cell.
Aside from the coding region of messenger RNA (mRNA) molecules that will be translated into proteins, other cellular RNA elements are involved in different processes.

What are RNA Origami?

RNA origami is the nanoscale folding of RNA, enabling the RNA to create particular shapes to organize these molecules.
It is an attempt to generate complex human-made RNA-based devices.
They 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.

(1) To achieve precise control of protein production

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.

(2) Using for gene editing

The RNA origamis were integrated in the small RNAs that guide CRISPR-Cas9 enzyme to target specific sequences in the DNA genome.
Its 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.