Question

the pribnow box of e. coli . question 15 options: a) is centered approximately 35 bp upstream of the start site of transcription b) is centered approximately 10 bp upstream of the start site of transcription c) is located at the site of addition of poly (a) in eukaryotic mrnas d) is centered between 7 and 13 bp upstream of the start codon

Answer 1

The Pribnow box of E. coli, a vital part of the promoter sequence, b) is centered approximately 10 bp upstream of the start site of transcription.

Step-by-step explanation:

Pribnow Box of E. coli

The Pribnow box of E. coli is a crucial part of the prokaryotic promoter which is located upstream of the gene that is being regulated.

This sequence is very important for the binding of RNA polymerase to initiate transcription. The Pribnow box, also known as the -10 sequence, is centered approximately 10 bp upstream of the start site of transcription (initiation site denoted as +1) and has the consensus sequence TATAAT.

This sequence, being A-T rich, helps in facilitating the unwinding of the DNA strand, which is necessary for the transcription process to begin.

On the other hand, the -35 sequence, with the consensus sequence TTGACA, is also an essential part of the promoter which is recognized and bound by the sigma factor of RNA polymerase.

It's important not to confuse this with the eukaryotic TATA box, which is similar but not identical to the prokaryotic Pribnow box.

Answering the student's question, the correct option is: b) is centered approximately 10 bp upstream of the start site of transcription.