Difference Between DNA and Protein Sequence

The key difference between DNA and protein sequence is that the DNA sequence is a series of deoxyribonucleotides bonded via phosphodiester bonds, while the protein sequence is a series of amino acids bonded via peptide bonds.

DNA is a type of nucleic acid. Protein is an essential macromolecule. Moreover, the DNA mainly stores the genetic information to make proteins. During that process, DNA transcribes into mRNA, and then mRNA translates into a protein. Thus, a DNA sequence finally converts into an amino acid sequence, which makes a protein.

CONTENTS

1. Overview and Key Difference
2. What is DNA Sequence
3. What is Protein Sequence
4. Similarities Between DNA and Protein Sequence
5. Side by Side Comparison – DNA vs Protein Sequence in Tabular Form
6. Summary

What is a DNA Sequence?

DNA (deoxyribonucleic acid) is a nucleic acid composed of deoxyribonucleotides. It contains information to make proteins. In simple words, DNA contains information of the cell required for making all proteins. There are four types of deoxyribonucleotides, depending on the nitrogenous base of the nucleotide. According to that, we can write a DNA sequence using four letters such as “ATGCGCTTAATTCCG” etc.

DNA mainly exists as double-stranded. Hence, there are two complementary DNA sequences in the DNA double helix. The two strands link with each other via hydrogen bonds created between purine and pyrimidine bases. The precise order of nucleotide sequence is vital. One base change may lead to a mutation, which can cause a fatal disease. Each gene has a unique DNA sequence. Similarly, the DNA fingerprint of each individual is unique and helps in their identification.

What is a Protein Sequence?

Protein is a polymer made up of different amino acids linked together via peptide bonds. Each protein has a unique amino acid sequence. Moreover, each protein has a gene encoding it. The amino acid sequence works as valuable information for its function, structure and evolution. There are twenty different amino acids that make proteins. Hence, an amino acid sequence of a protein can be a mixture of different amino acids.

An amino acid sequence has two terminals as amino-terminal (N terminal) and carboxyl-terminal (C terminal). When writing the amino acid sequence, it starts from the amino-terminal and goes towards the carboxyl-terminal.

Unlike DNA sequences, amino acid sequences are written by mentioning the three-letter code of each amino acid. Furthermore, one amino acid originates from three nucleotides that represent a codon. Thus, each codon is a mixture of three nucleotides. Nucleotide order in the codon will decide the amino acid that should be added to the polypeptide chain during the translation process.

What are the Similarities Between DNA and Protein Sequence?

• Both DNA and protein sequences are large complex molecules.
• DNA contains protein-synthesizing genetic information.
• DNA sequences and protein sequences are building blocks of life.

What is the Difference Between DNA and Protein Sequence?

A DNA sequence is a chain of deoxyribonucleotides while protein sequence is a chain of amino acids. So, this is the key difference between DNA and protein sequence. Phosphodiester bonds exist between deoxyribonucleotides of a DNA sequence while peptide bonds exist between amino acids in a protein sequence. Therefore, this is also a difference between DNA and protein sequence.

Below infographic shows more details on the difference between DNA and protein sequence.

Summary – DNA vs Protein Sequence

DNA sequence contains a series of deoxyribonucleotides. In contrast, protein sequence contains a series of amino acids. So, in summary, this is the key difference between DNA and protein sequence. Moreover, each nucleotide joins with the next nucleotide via phosphodiester bonds in a DNA sequence while each amino acid joins with the next amino acid via a peptide bond in a protein sequence. In each DNA sequence, there can be four different types of deoxyribonucleotides while in each protein sequence, there can be twenty different amino acids.

Reference:

1. “What Is DNA? – Genetics Home Reference – NIH.” U.S. National Library of Medicine, National Institutes of Health, Available here.
2. “Protein.” Wikipedia, Wikimedia Foundation, 6 Aug. 2019, Available here.

Image Courtesy:

1. “Genetic code” By Madprime – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Aasequencedirection*”By Lizanne Koch – lgkoch – own work with ChemBioDraw (Public Domain) via Commons Wikimedia