In eukaryotes, the terminator sequence for protein coding genes involves a _____ signal.

In eukaryotes, the terminator sequence for protein coding genes involves a _____ signal.

• A. Stop codon
• B. Poly A signal
• C. TATA box
• D. Poly C signal

Answer: (B)

The Poly A signal. In eukaryotes, termination of transcription for protein-coding genes is closely tied to mRNA processing: the pre-mRNA is cleaved downstream of the polyadenylation signal and a poly(A) tail is added. The Poly A signal (commonly AAUAAA in the RNA) is the cue recognized by processing factors to define the 3' end and enable polyadenylation, which helps disengage the polymerase and stabilize the transcript. The stop codon is a translation feature, not a transcription termination signal. The TATA box is part of the promoter region, not the terminator. Poly C is not a standard terminator/processing signal.

The Poly A signal.

In eukaryotes, termination of transcription for protein-coding genes is closely tied to mRNA processing: the pre-mRNA is cleaved downstream of the polyadenylation signal and a poly(A) tail is added. The Poly A signal (commonly AAUAAA in the RNA) is the cue recognized by processing factors to define the 3' end and enable polyadenylation, which helps disengage the polymerase and stabilize the transcript. The stop codon is a translation feature, not a transcription termination signal. The TATA box is part of the promoter region, not the terminator. Poly C is not a standard terminator/processing signal.