What are the differences between conservative and non-conservative missense mutation? explain with proper example.

Answer 1

A missense mutation is a point mutation (a single nucleotide substitution) that may result in an amino acid substitution.

A conservative missense mutation is where the resultant amino acid is the same or has similar properties to the substituted amino acid e.g if a hydrophobic amino acid is replaced by another hydrophobic amino acid, it is highly unlikely that this substitution will have any effect on the protein structure and function; therefore since there will be little to no change as a result of the mutation (and subsequent amino acid substitution), this would be classified as a conservative missense mutation.

A non-conservative missense mutation is where the resultant amino acid has different properties from the original amino acid e.g when a non-polar amino acid is substituted for a charged, polar amino acid, this will most likely result in a change in the protein's shape and function. This is in fact the case in sickle-cell anemia, where valine, a non-polar and hydrophobic amino acid, is replaced by glutamic acid, a charged and acidic amino acid. This substitution results in a fundamental change in the shape of hemoglobin and is the primary contributor to the pathology associated with sickle cell anemia.