nonsense mutation

views updated Jun 11 2018

nonsense mutation A mutation that alters a gene so that a nonsense codon is inserted. Such a codon is one for which no normal t-RNA molecule exists: the codon therefore does not code for an amino acid. Usually a nonsense codon causes the termination of translation (i.e. the end of the polypeptide chain). Three nonsense codons are recognized, and are called the amber, ochre, and opal codons.

nonsense mutation

views updated May 21 2018

nonsense mutation A mutation that alters a gene so that a nonsense codon is inserted. Such a codon is one for which no normal t-RNA molecule exists; the codon therefore does not code for an amino acid. Usually a nonsense codon causes the termination of translation (i.e. the end of the polypeptide chain). Three nonsense codons are recognized, and are called the amber, ochre, and opal codons.

nonsense mutation

views updated May 21 2018

nonsense mutation A type of point mutation that converts a codon normally specifying an amino acid to one of the stop codons, thus signalling termination of translation and causing synthesis of the polypeptide chain to cease prematurely.

nonsense mutation

views updated Jun 11 2018

nonsense mutation A mutation which results in a nonsense codon.