A mutation occasionally arises that converts a codon

Last updated: 4/1/2023

A mutation occasionally arises that converts a codon specifying an amino acid to a stop or nonsense codon When this occurs in the middle of a gene the resulting protein is truncated and often inactive If the protein is essential cell death can result Which of these secondary mutations might restore some or all of the protein function so that the cell can survive a mutation changing the nonsense codon to one encoding a different but similar amino acid a mutation in the anticodon of a tRNA such that the tRNA now recognizes the nonsense codon a mutation restoring the codon to the one encoding the original amino acid a mutation in which an additional nucleotide inserts just upstream of the nonsense codon changing the reading frame so the nonsense codon is no longer read as stop