Several types of mutation are identified and described in the chapter. These include (1) promoter mutation, (2) splice site mutation, (3) missense mutation, (4) frameshift mutation, and 5) nonsense mutation. Match the following mutation descriptions with the type(s) of mutations listed above. More than one mutation type might match a description.

A mutation that produces a mutant protein that differs from the wild-type protein at one amino acid position.

Key Concepts

Missense Mutation

A missense mutation is a type of point mutation where a single nucleotide change results in the substitution of one amino acid for another in the protein sequence. This alteration can affect the protein's function, depending on the role of the specific amino acid in the protein's structure and activity. For example, if the substituted amino acid is critical for the protein's active site, the mutation may lead to a loss of function.

Wild-Type Protein

The wild-type protein refers to the normal, non-mutated version of a protein that is typically produced by a gene. It serves as the standard against which mutant proteins are compared. Understanding the wild-type protein's structure and function is essential for assessing the impact of mutations, such as missense mutations, on protein activity and overall cellular function.

Protein Structure and Function

The structure of a protein is intricately linked to its function, as the specific arrangement of amino acids determines how the protein folds and interacts with other molecules. Changes in the amino acid sequence, such as those caused by missense mutations, can lead to alterations in the protein's three-dimensional shape, potentially disrupting its biological activity. This relationship is crucial for understanding the consequences of genetic mutations on health and disease.