Question

What is an example of missense mutation?

Answer 1

Missense mutation:

1. This is a type of base substitution (purine substituted by purine or pyrimidine substituted by pyrimidine) in which the change in a nucleotide in the same position results in the formation of a codon that replaces one amino acid with another amino acid.

Example of missense mutation:

1. Suppose a double-stranded DNA molecule has a nucleotide sequence AAA (5'-3') and the complementary sequence TTT (3'-5').
2. If a missense mutation occurs the nucleotide sequence Adenine gets substituted by Guanine, om transcription of this mutated nucleotide sequence results in mRNA with GAA codon.
3. On translation the codon AAA codes for amino acid lysine but after mutation the codon GAA codes for Glutamine amino acid.