The sigma-70 subunit
A)increases the affinity of the core polymerase for nonpromoter sequences.
B)decreases the affinity of the core polymerase for specific promoter sequences.
C)is responsible for transcribing many genes.
D)is associated with a holoenzyme,enabling the formation of more stable complexes.
E)All of the above.

Question

Quizplus · Accepted Answer

The sigma-70 subunit is associated with a holoenzyme, which contains the core polymerase and enables the formation of more stable complexes. This stabilizes the interaction between the RNA polymerase and the promoter sequences, leading to efficient transcription initiation. The sigma-70 subunit does not usually affect the affinity of the core polymerase for non-promoter sequences, nor does it decrease the affinity of the core polymerase for specific promoter sequences. While sigma-70 is responsible for transcribing many genes, this function is not directly related to its role in stabilizing the holoenzyme.

The Sigma-70 Subunit