Question

RNAP changes conformation during the transcription cycle. Given below are stages of transcription and the amount of promoter DNA that is protected from DNase digestion: Which one is NOT correct?

A. Ternary enzyme complex; -34/+20

B. Elongation complex: -75/+20

C. Closed promoter complex; -55/+1

D. Opened promoter complex; -55/+20

Answer 1

The correct range for the footprint of the opened promoter complex is typically -55 to +15 or -10 to +2, not -55 to +20. The option that is NOT correct is D. Opened promoter complex; -55/+20.

Step-by-step explanation:

The correct answer is D. Opened promoter complex; -55/+20 is NOT correct.

In transcription, RNA polymerase (RNAP) progresses through various stages, each associated with specific regions of the promoter. The given options describe the protected regions of promoter DNA during these stages:

A. Ternary enzyme complex; -34/+20: This corresponds to the region between nucleotides -34 and +20, indicating the footprint of the ternary complex during transcription initiation.

B. Elongation complex: -75/+20: This refers to the region between nucleotides -75 and +20, which represents the footprint during the elongation phase of transcription.

C. Closed promoter complex; -55/+1: This corresponds to the region between nucleotides -55 and +1, indicating the footprint during the closed promoter complex formation.

D. Opened promoter complex; -55/+20: This option is incorrect. The correct range for the opened promoter complex is typically -55 to +15 or -10 to +2, not -55 to +20.