Which type of cell has a TATA box in promoter regions?

• A. Prokaryotes
• B. Eukaryotes
• C. Both
• D. None

Answer: (B)

Promoter architecture and how transcription starts differ between cell types. A TATA box is a specific DNA sequence found upstream of the transcription start site in many eukaryotic genes. It typically sits about 25 to 35 bases before the start and has the consensus sequence TATAAA. This element helps recruit transcription factors, especially the TATA-binding protein, which is part of the transcription factor II D complex, and that recruitment positions RNA polymerase II to begin transcription.

Prokaryotes, in contrast, use promoter elements such as the -35 and -10 regions and rely on sigma factors to recruit RNA polymerase. They don’t use a TATA box for initiating transcription. While archaea share some features with eukaryotes, the classic promoter element called the TATA box is characteristic of eukaryotic promoters. So, presence of a TATA box points to a eukaryotic cell.