試題詳解

44. How does binding of the lac repressor to the lac operator block transcription initiation?
(A) lac repressor binding blocks RNA polymerase from interacting with DNA at the start site.
(B) lac repressor binding induces a DNase that cleaves the DNA at the transcription start site.
(C) lac repressor binding causes a conformational change in RNA polymerase.
(D) lac repressor binding induces a protease that degrades the sigma subunit of RNA polymerase.
(E) all of the above.