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Point Mutations: Nonsense

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State

A nonsense mutation changes a codon into a premature stop codon, ending translation early and producing a shortened, usually nonfunctional protein.

Show

A single base change converting a tyrosine codon into a stop codon halts the ribosome partway through the intended protein.

Watch for

A nonsense mutation is a single base change like missense, but its effect on the protein is far more disruptive.