D614G MUTANT VIRUS

D614G MUTANT VIRUS

Subject : Science & technology

Context : A team of scientists at the National Institute of Biomedical Genomics (NIBMG) in Kalyani has pointed to a biological reason behind the slower spread of the D614G mutant coronavirus in Asia compared to Europe and the USA.

Concept :

D614G mutation

• When the virus enters an individual’s body, it aims at creating copies of itself. When it makes an error in this copying process, we get a mutation.
• In this case, the virus replaced the aspartic acid (D) in the 614th position of the amino acid with glycine (G). Hence the mutation is called the D614G.
• D614G Mutation: This particular mutation aided the virus in attaching more efficiently with the ACE2 receptor in the human host, thereby making it more successful in entering a human body than its predecessors.
• D614G showed increased infectivity but it also displayed greater ability at attaching itself to the cell walls inside an individual’s nose and throat, increasing the viral load.
• This mutated form of the virus was first identified in China and then in Europe. Later it spread to other countries like the U.S. and Canada and was eventually reported in India.

Mutation

• A mutation means a change in the genetic sequence of the virus.
• In the case of SARS-CoV-2, which is an Ribonucleic acid (RNA) virus, a mutation means a change in the sequence in which its molecules are arranged.
• SARS-CoV-2 is the virus that causes Covid-19.
• RNA is an important biological macromolecule that is present in all biological cells.
• Principally involved in the synthesis of proteins, carrying the messenger instructions from Deoxyribonucleic Acid (DNA), which itself contains the genetic instructions required for the development and maintenance of life.
• DNA is an organic chemical that contains genetic information and instructions for protein synthesis. It is found in most cells of every organism.
• A mutation in an RNA virus often happens when the virus makes a mistake while it is making copies of itself.
• Only if the mutation results in a significant change in the protein structure can the course of a disease be altered.