Question

In prokaryotes, holoenzyme RNA polymerase attaches to the DNA sequence at the promoter site of template DNA during transcription. The sequence of that point where the RNA polymerase binds is:

Answer 1

The DNA sequence to which RNA polymerase binds to initiate transcription is called the promoter region.

The region upstream of the transcription initiation site contains two sets of sequences.

These sequences encompass six nucleotides each, and are located approximately 10 and 35 base pairs upstream of the transcription start site.

They are called the -10 (TATAAT) and -35 (TTGACA) elements, commonly referred to as TATA box or pribnow box.

The diagram below shows the TATA box or pribnow box at the promoter site with sequence TATAAT. It also shows that the sigma factor of RNA polymerase recognises the TATAAT and TTGACA sequences and binds there.