What is the difference between a transition mutation and a transversion mutation?

Key Concepts

Transition Mutation

A transition mutation is a type of point mutation where a purine base (adenine or guanine) is replaced by another purine, or a pyrimidine base (cytosine or thymine) is replaced by another pyrimidine. This type of mutation is more common than transversion mutations and often has less impact on the protein structure, as it maintains the same class of nucleotide.

Transversion Mutation

A transversion mutation is another type of point mutation, but it involves the substitution of a purine for a pyrimidine or vice versa. This means that adenine or guanine can be replaced by cytosine or thymine, leading to a more significant change in the DNA sequence. Transversions are less frequent than transitions and can have a greater impact on the resulting protein.

Impact on Protein Function

Both transition and transversion mutations can affect protein function, but their impacts can vary. Transition mutations are often less disruptive due to the preservation of the nucleotide class, while transversions can lead to more drastic changes in amino acid sequences, potentially altering protein structure and function. Understanding these differences is crucial for predicting the effects of mutations in genetic studies.