Difference Between DNA-RNA Hybrids and dsDNA

The key difference between DNA-RNA hybrids and dsDNA is that DNA-RNA hybrids are double-stranded nucleotides composed of one DNA strand and one complementary RNA strand while dsDNA is a double-stranded DNA composed of two complementary DNA strands.

In its native state, DNA is double-stranded. It has two complementary DNA strands bonded via hydrogen bonds. RNA is single-stranded in its native structure. In some instances, RNA form duplexes with DNA. They are known as DNA-RNA hybrids. They are mainly formed during the transcription and multiplication of oncogenic RNA viruses. In comparison to dsDNA, DNA-RNA hybrids are more stable.

CONTENTS

1. Overview and Key Difference
2. What are DNA-RNA Hybrids 
3. What is  dsDNA
4. Similarities Between DNA-RNA Hybrids and dsDNA
5. Side by Side Comparison – DNA-RNA Hybrids and dsDNA in Tabular Form
6. Summary

What are DNA-RNA Hybrids?

DNA-RNA hybrids are nucleic acids composed of one DNA strand and one complementary RNA strand. They form during transcription when the RNA and DNA are in close proximity. Moreover, DNA-RNA hybrids form during the multiplication of oncogenic RNA viruses.

Generally, DNA-RNA hybrids are abundant in human cells. They are more stable than double-stranded DNA. When DNA-RNA hybrids are formed, one DNA strand displaces. It is known as an R loop. These R loops are mostly deleterious since they can cause DNA damages.

What is dsDNA?

dsDNA or double-stranded DNA is a nucleic acid composed of two DNA strands. These two DNA strands are complementary to each other. Moreover, they wind around each other like a twisted ladder. Backbones of two strands consist of sugar and phosphate groups.

There are four different nitrogenous bases as A, G, C and T. Two strands are bonded to each other by hydrogen bonds formed between bases. Adenine forms a pair with thymine. Cytosine forms a pair with guanine. The structure of DNA helix was described by Watson and Crick in 1953. This DNA double helix has the genetic information of an organism. DNA can be replicated as well as repaired. Most DNA double helices are right-handed. Moreover, dsDNA is anti-parallel. Therefore, 5’ end of one strand is paired with 3’ end of the other strand.

What are the Similarities Between DNA-RNA Hybrids and dsDNA?

• DNA-RNA hybrids and dsDNA are nucleic acids.
• Both DNA-RNA hybrids and dsDNA are double-stranded, composed of two complementary polynucleotide strands.
• Two strands of both DNA-RNA hybrids and dsDNA are connected by hydrogen bonds.

What is the Difference Between DNA-RNA Hybrids and dsDNA?

DNA-RNA hybrids are nucleic acids composed of a DNA strand and a complementary RNA strand, while dsDNA is a nucleic acid composed of two complementary DNA strands. So, this is the key difference between DNA-RNA hybrids and dsDNA.

Moreover, another important difference between DNA-RNA hybrids and dsDNA is that the DNA-RNA hybrids are more stable than the dsDNA.

Below infographic shows some significant differences between DNA-RNA hybrids and dsDNA.

Summary – DNA-RNA Hybrids vs dsDNA

DNA-RNA hybrids and dsDNA are two types of nucleic acids composed of polynucleotides. Both are double-stranded. However, DNA-RNA hybrids have one DNA strand and one RNA strand while dsDNA has two DNA strands. Thus, this is the key difference between DNA-RNA hybrids and dsDNA. DNA-RNA hybrids are formed during the transcription. Moreover, they are stable than dsDNA.

Reference:

1. Wang1, Isabel X., et al. “Isabel X. Wang.” Genome Research, Cold Spring Harbor Lab, 1 Jan. 1970, Available here.
2. “Discovery of DNA Structure and Function: Watson and Crick.” Nature News, Nature Publishing Group, Available here.

Image Courtesy:

1. “R loop S9.6 mAb.” By Kmnip – Own work (CC BY 3.0) via Commons Wikimedia
2. “DNA chemical structure” By Madprime (talk · contribs) – Own workiThe source code of this SVG is valid. This vector image was created with Inkscape (CC BY-SA 3.0) via Commons Wikimedia