What mutation results in changing an amino acid codon to a stop codon, leading to a nonfunctional protein?

A nonsense mutation is characterized by a change in the DNA sequence that converts an amino acid codon into a stop codon. When this occurs, the protein synthesis process is terminated prematurely, resulting in a truncated protein that is typically nonfunctional. This type of mutation alters the normal reading frame of the genetic code, leading to the production of a significantly shorter polypeptide chain that lacks essential functional domains necessary for the protein’s activity.

The nature of this mutation can be particularly detrimental, as the resulting protein may fail to perform its intended biological role within the cell. This is significantly different from other types of mutations. A substitution generally refers to a change in a single nucleotide that may or may not affect the function of the protein, depending on whether it results in a different amino acid or a stop codon. Insertion refers to the addition of one or more nucleotides, which can lead to a frameshift mutation, altering the reading frame and potentially leading to a nonfunctional protein but does not specifically create a stop codon. A frameshift mutation, while it can result in a nonfunctional protein, does not specifically denote a change to a stop codon, which is the defining characteristic of a nonsense mutation.

Thus, the specific mechanism of