What is the termination sequence in transcription for eukaryotes?

In eukaryotic transcription, the termination sequence is a signal that indicates where the transcription of a gene should stop. The sequence AAUAAA is a polyadenylation signal that plays a crucial role in the termination of transcription for protein-coding genes.

After RNA polymerase synthesizes a pre-messenger RNA (pre-mRNA) molecule, the presence of this AAUAAA sequence is recognized by specific proteins that facilitate the cleavage of the pre-mRNA and the addition of a poly(A) tail. This process stabilizes the mRNA for export from the nucleus and protects it from degradation in the cytoplasm. The cleavage occurs shortly after the RNA polymerase transcribes the AAUAAA signal, which marks the end of the transcription elongation process.

Understanding this mechanism is vital because the precise termination of transcription ensures that the appropriate mRNA length is achieved, which is essential for the correct encoding of proteins during translation.