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Which codons signal the end of protein translation?
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Nucleic acid
A portion of the polynucleotide chain of deoxyribonucleic acid (DNA), with an inset showing the corresponding pentose sugar and pyrimidine base in ribonucleic acid (RNA).
In the process of protein synthesis, the end of translation is signaled by specific sequences of three nucleotides known as termination or stop codons. These codons do not specify an amino acid but instead trigger the dissociation of the ribosome, the newly synthesized protein, and the messenger RNA (mRNA) through the association of special release factors.12
The three codons that serve as stop signals are:
- UAG
- UAA
- UGA
When the ribosome encounters one of these triplets along the mRNA sequence, it ceases the addition of amino acids, effectively terminating the assembly of the protein chain.12