試題詳解

14. Which of the following regarding structural basis of eukaryotic RNA polymerase II and its nucleotide selection is     not true    ?
(A) Structure of yeast RNA polymerase II shows a deep cleft that is lined with basic amino acids and can accept a linear DNA template.
(B) From structure of yeast RNA polymerase II, there is a funnel-shaped pore in the bottom of the enzyme and this pore may serve as the exit point for extruding the 3'-end of the nascent RNA.
(C) To understand how RNA polymerase II can discriminate against dNTPs, Kornberg and colleagues found that the enzyme incorporated ribonucleotides at a much slower rate than it did deoxyribonucleotides.
(D) When a correct nucleotide occupies the nucleotide-binding "A" site, the trigger loop of Rpbl makes several important contacts with that nucleotide to presumably stabilize the nucleotide's association with the active site.
(E) The metal B enters the active site of RNA polymerase II by forming complex with the incoming nucleotide.