Protein synthesis concludes through a process involving specific signals within the messenger RNA (mRNA) and release factors. Termination occurs when the ribosome encounters a stop codon (UAA, UAG, or UGA) in the mRNA sequence. These codons do not code for any amino acid. Instead, they signal the halt of polypeptide chain elongation.
The accurate ending of protein production is vital for cellular function. Premature or failed termination can lead to the production of truncated or aberrant proteins, potentially disrupting cellular processes and contributing to disease. The termination mechanism ensures that each protein is synthesized to its correct length and with the appropriate amino acid sequence, contributing to the overall fidelity of the proteome. Understanding the termination phase also provided key insights into the mechanism of translation process.