What acts as the nucleophile in the mechanism of nucleotide addition by RNA polymerase?
A) the 5' phosphate of an incoming nucleotide
B) a water molecule
C) a 5' hydroxyl of the template DNA
D) a 3' hydroxyl from the RNA being extended
E) an aspartate in the active site

Question

Quizplus · Accepted Answer

The 3' hydroxyl from the RNA being extended acts as the nucleophile in the mechanism of nucleotide addition by RNA polymerase, attacking the alpha phosphate of the incoming nucleotide to form a new phosphodiester bond.

What Acts as the Nucleophile in the Mechanism of Nucleotide