Question

For eukaryotic genes, the core promoter typically consists of a TATAAA sequence called the _________ box and the transcriptional start site.

Answer 1

The TATA box is the component of the eukaryotic core promoter that precedes the transcriptional start site and plays a crucial role in the initiation of transcription by binding a protein complex that recruits RNA polymerase.

Step-by-step explanation:

For eukaryotic genes, the core promoter typically consists of a TATAAA sequence called the TATA box and the transcriptional start site. This TATA box, located 25 to 35 bases upstream of the transcriptional start site, is essential for the binding of the protein complex TFIID, which contains a TATA-binding protein. The binding of TFIID and subsequent recruitment of other transcription factors such as TFIIB, TFIIE, TFIIF, and TFIIH, enable the RNA polymerase to bind to the promoter, thus initiating gene transcription.

Some promoters may also include a conserved CAAT box (GGCCAATCT) approximately 80 bases upstream and other elements like GC-rich boxes (GGCG) or octamer boxes (ATTTGCAT). These additional elements assist in enhancing the efficiency of transcription initiation, particularly in genes that are constantly expressed within the cell. The combination of these various factors ensures that only the necessary genes are transcribed in any given cell type, enabling the diverse functions that cells perform.