Question

When considering the initiation of transcription, one often finds consensus sequences located in the region of the DNA where RNA pol binds. Which of the following is a common consensus sequence

a. TATA
b. any trinucleotide repeat
c. satellite DNAs
d. GGTTC
e. TTTAAAA

Answer 1

A common consensus sequence for transcription initiation is the TATA box, consisting of the sequence 5'-TATAAA-3' in eukaryotes and 'TATAAT' in prokaryotes, located in the promoter region upstream of the gene.

Step-by-step explanation:

When considering the initiation of transcription, a common consensus sequence found at the region where RNA polymerase binds is the TATA box. This consensus sequence is 5'-TATAAA-3' and is located within the core promoter region, usually 25 to 35 bases upstream of the transcription start site in eukaryotic organisms. In prokaryotes, a similar sequence known as the -10 region is also important for transcription initiation and has the consensus sequence TATAAT. Additionally, prokaryotes have a -35 consensus sequence of TTGACA, which is critical for the binding of transcription factors.

Promoters are essential as they determine the frequency of transcription for a given gene. Other consensus sequences like the CAAT box and GC-rich boxes enhance transcription efficiency, particularly in eukaryotic promoters.