Which does not occur during the hydrolysis of RNA by RNase A?
A)Covalent catalysis involving a bond between a pyrimidine and a lysine of RNase A.
B)Acid-base catalysis to cleave the phosphodiester bond.
C)Abstraction of a proton from the 2'-hydroxyl group by histidine.
D)Transition-state stabilization of a pentavalent phosphorous atom.

Question

Quizplus · Accepted Answer

Covalent catalysis involving a bond between a pyrimidine and a lysine of RNase A does not occur during the hydrolysis of RNA by RNase A. This is because RNase A is a protein enzyme that catalyzes the cleavage of phosphodiester bonds in RNA molecules through acid-base catalysis and transition-state stabilization of a pentavalent phosphorous atom. Histidine may also act as a general base to abstract a proton from the 2'-hydroxyl group of the ribose sugar during the reaction. However, there is no covalent bond between a pyrimidine and a lysine residue in RNase A that is involved in the hydrolysis of RNA.

Which Does Not Occur During the Hydrolysis of RNA by RNase