試題詳解

39. Which of the following descriptions about 3' mRNA end processing is not correct?
(A) The site of cleavage/polyadenylation is flanked by an upstream AAUAAA motif and a downstream U-rich or GU-rich element.
(B) The cleavage and polyadenylation specific factor (CPSE): One subunit binds to the AAUAAA motif and to the cleavage stimulatory factor (CstF). One binds to downstream GU-rich sequence.
(C) CPSF and CstF enhance each other.
(D) The enzyme 73-kDa CPSF subunit cleaves the RNA.
(E) Poly(  A )-binding protein synthesizes the poly( A ) tail.