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trinucleotide sequence (UAA, UGA, or UAG) that specifies the end of translation or transcription. Compare: amber codon, ochre codon, umber codon.
Farlex Partner Medical Dictionary © Farlex 2012
stop codonAny of the 3 codons (or triplets of nucleotides—UAA, UAG and UGA) on an mRNA molecule which lack a cognate aminoacyl tRNA—i.e., do not code for an amino acid and thus signal the end of protein synthesis. When ribosomes hit a stop codon, mRNA transcription is terminated, causing polypeptide synthesis to stop and the ribosome to dissociate from the mRNA.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
nonsense codonOne of the three nucleotide triplets (codons), UAG, UAA or UGA that mark an end point to a particular protein synthesis. U is the base uracil; A is the base adenine; and G is the base guanine.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005