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Difference Between DNAs and DNase

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What is DNAs and DNase?: An Introduction

To understand DNAs and DNase difference, it is important to know what they are. DNA and DNase are both present inside the cell in all living organisms and serve crucial functions. Here's a description of the characteristics of DNAs and DNase.

Last updated date: 21st Sep 2023
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DNase: DNase (Deoxyribonuclease)

DNAae is a group of enzymes composed of amino acids linked with peptide bonds, like any other protein. It plays a vital role in the degradation and breakdown of DNA molecules, thereby striking a balance between DNA synthesis and turnover. DNase enzymes are of three types, namely, DNase I, DNase II, and DNase III (also known as TREX1), which differ in their mechanism of action. DNase I cleaves the 5’ to 3’ phosphodiester bonds that  DNA, resulting in that holds the nucleotides. This leads to fragmentation of the DNA into smaller fragments. 

DNase I requires divalent cations for their activity and works best in alkaline pH. DNase II functions in the degradation of DNA fragments within the lysosomes of cells in an acidic environment. However, DNase II does not need any cation-mediated activation. DNase III/TREX1 is the third category of DNase which acts as an exonuclease. The DNase family of enzymes are involved in biological processes like the breakdown of DNA during DNA damage repair and the regulation of immune responses.

Differences Between DNA and DNase





Structure and Composition

DNA is a double helical structure which consists of nucleotides.  

DNase is a protein and thus comprises basic units called amino acids.


The monomeric units or the nucleotides that comprise the DNA are linked to one another with a 5’ to 3’ phosphodiester bond.

The amino acids that comprise the protein DNase are linked through peptide linkage. 


  • DNA makes up the genetic material for all living organisms from prokaryotes to higher eukaryotes.

  • It contains all the genetic information and plays a crucial role in genetic inheritance. 

  • DNA acts like a blueprint for the synthesis of proteins that essentially carry out functions necessary for the growth, development, metabolism and propagation of the organism. 

  • DNase is an enzyme that cleaves the 5’ to 3’ phosphodiester bond of the DNA and degrades the DNA into smaller fragments. 

  • It allows the degradation and recycling of the DNA monomer, thereby maintaining a balance between DNA synthesis and turnover. 

  • It serves an important role in many biological processes like DNA repair and more. 

  • Its role is indispensable in regulating the levels of DNA and its integrity.


DNA is present within the nucleus of the cell. In eukaryotes, the DNA wraps around the histone octamers and condenses into higher order structure to form the chromatin. 

DNAse being a protein is translated in the cytoplasm with the help of the ribosomes. They act on extracellular DNA.


DNA may be nuclear, mitochondrial or plastidial. In bacteria, episomal DNA or plasmid DNA also exist alongside chromosomal DNA. In humans, DNA exists in three forms. They are A, B and Z-DNA.

DNase can be classified into two families, DNase I and DNase II. The former requires the presence of cations for their activation unlike the latter. There is also a third category called DNAseIII which acts like an exonuclease.


Laboratory uses

DNA finds its application in genetic engineering, molecular biology techniques like cloning, PCR and genetic manipulations.

DNase is used in:

  • The laboratory for RNA isolation processes to remove residual DNA contaminants from the RNA sample.

  • The DNAse footprinting assay to determine protein-DNA interaction to the exact nucleotide region. 


This article sheds light on the differences between the DNA and DNase. It also explains what is DNAs and DNase, and elaborates their characteristics. DNA is a nucleotide that acts as a blueprint for the genetic makeup of an organism, while DNase is a protein which functions as an enzyme in the hydrolysis of the phosphodiester bond in the DNA.

FAQs on Difference Between DNAs and DNase

1. What is the primary difference between DNAs and DNase?

It is crucial to understand the characteristics of DNAs and DNase to learn their differences. DNA is a molecule that carries genetic information and serves as the blueprint for living organisms. Its basic constituents are nucleotides that are linked through phosphodiester bonds. DNase, on the other hand, is an enzyme that specifically breaks down DNA molecules into smaller fragments by cleaving the phosphodiester bonds between nucleotides. It is protein by nature, and thus amino acids as its building block.

2. What are the respective functions of DNA and DNase in biological processes?

DNA is a molecule that acts as the genetic material of all living organisms, including some viruses. It functions in protein synthesis, gene regulation, development and inheritance. DNase is involved in DNA degradation, participating in cellular processes like DNA repair, apoptosis, and defense against foreign DNA. DNase maintains DNA balance, preventing excessive or damaged DNA accumulation.

3. What are the different types of DNA and DNase?

DNA can be chromosomal, which is present within the nucleus. It can also be mitochondrial or plastidial, contained within the mitochondria and the chloroplast, respectively. Apart from that plasmid DNA exists in bacteria which are extrachromosomal. Each of these DNAs possesses distinct functions. In humans, DNA exists in three forms - A, B and Z form. DNase is a group of enzymes that has three distinct families. They are DNase I, DNase II and DNase III. These enzymes have different modes of action and are functional at different pH and different conditions.