A mutation from G ➡ A causes a protein to lose its activity. Which level of protein structure is most likely affected and how?
Point mutation is called mutation in a gene in which one base pair in the DNA sequence is altered. Such that in above example G is mutated or altered to A.
There are two types of point mutations:
– transition mutations
– transversion mutations.
As above example in question shows example of transition. It is a point mutation that changes a purine nucleotide to another purine (A to G) or a pyrimidine nucleotide to another pyrimidine (C to T).
In translation, RNA copied from DNA is transformed to amino acids during protein synthesis, point mutations appear as modifications in the final protein product.
Thus, there exist useful groupings for factor mutations. These groupings are divided into :
How they affect protein structure:
Silent mutations bring about a brand new codon (a triplet nucleotide series in RNA) that codes for the identical amino acid because the wild kind codon in that function. In a few silent mutations the codon codes for a unique amino acid that happens to have the same houses because the amino acid produced by the wild type codon.
Missense mutations contain substitutions that result in functionally extraordinary amino acids; those can cause alteration or lack of protein feature.
Nonsense mutations, which might be a intense kind of base substitution, bring about a prevent codon in a role wherein there was no longer one earlier than, which reasons the untimely termination of protein synthesis and, more than probably, a complete lack of function within the finished protein.