試題詳解

47. Which of the following statements correctly describes promoters in E. coli?
(A) A promoter may be present on either side of a gene or in the middle of it.
(B) All promoters have the same sequence that is recognized by RNA polymerase holoenzyme.
(C) Every promoter has a different sequence, with little or no resemblance to other promoters.
(D) Many promoters are similar and resemble a consensus sequence, which has the highest affinity for RNA polymerase holoenzyme.
(E) Promoters are not essential for gene transcription, but can increase its rate by two- to three-fold.