Question

You have one protein to mutate one specific residue to another. For example, the residue 50 of glutamate is designed to be substituted with alanine. What kind mutation technique will you use for this purpose. Please explain your chosen mutation method in detail.

Answer 1

Ans. Change of one amino acid residue into another residue in a protein due to point mutation / base substitution mutation in its DNA/ gene is called as animo acid replacement. It is also called as missense mutation.

Replacement of specific residue by other desired residue can be carried out by an artificial method known as site-derected mutation techniques (site-directed mutagenesis). By this site directed mutagenesis we can change the nucleotides of the codon in the gene/ DNA encoding the target residue in the protein.

There are several ways to induse site specific mutation in DNA but one of most cost effective and specific method is artificial gene synthesis (which includes DNA printing and DNA assembly in synthesis biology). By de novo synthesizing a gene artificially in laboratory with desired squence/ desired change in DNA / gene sequence at desired location, we can synthesize the mutated gene in laboratory and the same gene can be clonned to express the mutated protein.

Now a days genome editing by using CRIPSR can be used to change a specific DNA nucleotide in vivo to create site directed mutagenesis.