試題詳解

24. Both the catabolite activator protein (CAP) and the Lac repressor can bind DNA, but why does CAP facilitate transcription while the Lac repressor represses transcription?
(A) CAP and the Lac repressor use different structural motifs to bind DNA.
(B) CAP binds to the region overlapping the promoter, while the Lac repressor binds to the region at a distance from the promoter.
(C) The Lac repressor can interact with the RNA polymerase to inhibit transcription.
(D) CAP has an activating surface that recruits the RNA polymerase.
(E) CAP binds as a homodimer, while the Lac repressor binds as a homotetramer.