Nonsense mutation
A mutation (a change) in a base in the DNA that prematurely stops the translation (reading) of messenger RNA (mRNA) resulting in a polypeptide chain that ends prematurely and a protein product that is truncated (abbreviated) and incomplete and usually nonfunctional. The nonsense mutation converts a codon (a triplet of bases) that encodes an amino acid into a stop codon, one that specifies the termination of translation. There are three nonsense codons (UAG, UAA, and UGA) in mRNA. One of them comes normally at the end of each polypeptide. A nonsense codon is a stop codon which is out of place. Catching such a defective messenger RNA (mRNA) before a truncated and potentially harmful protein is synthesized is the job of what is called the nonsense-mediated mRNA decay (NMD) pathway.

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a mutation in which one of the three termination codons in the mRNA (UAG, amber; UAA, ochre; UGA, umber or opal), used to signal the end of a polypeptide, appears in the middle of a genetic message, causes premature termination of transcription, and results in the production of an incomplete, generally nonfunctional polypeptide. See also missense m.

Medical dictionary. 2011.

Look at other dictionaries:

  • nonsense mutation — nonsense mutation. См. нонсенс мутация. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Nonsense mutation — In genetics, a nonsense mutation is a point mutation in a sequence of DNA that results in a premature stop codon, or a nonsense codon in the transcribed mRNA, and in a truncated, incomplete, and usually nonfunctional protein product. It differs… …   Wikipedia

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  • nonsense mutation — Mutation in coding DNA that prevents the protein from being synthesized …   Dictionary of molecular biology

  • nonsense mutation — A mutation that converts a sense codon to a nonsense or stop codon …   Dictionary of microbiology

  • nonsense mutation — A mutation that changes a coding triplet into a triplet that codes for no amino acid and terminates the polypeptide chain …   Dictionary of invertebrate zoology

  • nonsense mutation — noun A point mutation that generates either a premature stop codon, or a codon that does not specify any amino acid …   Wiktionary

  • nonsense mutation — A mutation which converts an amino acid specifying codon into a stop codon, e.g. a single base change from UAU to UAG generates the premature termination of the polypeptide chain at the position where a tyrosine was incorporated in the wild type …   Glossary of Biotechnology

  • Nonsense (disambiguation) — Nonsense is an utterance or written text that does not in fact carry any identifiable meaning. Nonsense may also mean: Abstract nonsense, a term used by mathematicians to describe certain kinds of arguments and concepts in category theory In… …   Wikipedia

  • Mutation — For other uses, see Mutation (disambiguation). Part of the Biology series on Evolution …   Wikipedia

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