Question

What is the difference between double helix, triple helix and quadriplex              structure in in nucleic acid molecules? How are these formed? Which one is most stable and why? Can they contribute in DNA origami where you can make nano structures like cube boxes, etc.

Answer 1

Ans. Double- stranded DNA :-  The double - stranded DNA consists of two polynucleotide chains whose nitrogenous bases are connected by hydrogen bonds.

It is the major form of genetic material in most organisms.

Triple- stranded DNA ( also known as H- DNA) :- It is a DNA structure in which three oligonucleotides wind around each other and form a triple helix. In triple - stranded DNA , the third strand binds to a B- form DNA double helix by forming Hoogsteen base pairs.

Quadriplex DNA :-   A single strand of DNA can fold onto itself to form a G -quadruplex, or guanines from multiple strands can bond to form the four - stranded DNA structure. These G's are held together with hydrogen bonds.

In forming a triple helix, RNA is favored on both pyrimidine strands, whereas DNA is favored on the purine strand. In general, relatively unstable duplexes form particularly stable triplexes and vice versa.

The DNA double helix is the most stable DNA.

The DNA double helix scaffold can be directly used to fabricate integrated DNA origami structures that incorporate both of the constituent ssDNA molecules.

Yes , All these three helix ( double helix, triple helix, quadriplex) contribute in the DNA origami.