A prokaryotic replisome typically contains two molecules of DNA pol III,but only one molecule of DNA pol I.Why?
A) The DNA pol I works on the leading strand, while DNA pol IIIs work on the Okazaki fragments. since there are several of those, it takes more proteins to keep up.
B) DNA pol I has a built-in proofreading exonuclease; DNA pol III does not. The second DNA pol III is needed to follow the first to accomplish the necessary proofreading.
C) The DNA pol IIIs do most of the work. DNA pol I only has to work on the telomers.
D) DNA pol I replaces the RNA primers with DNA, which really only needs to be done repetitively on one strand, while both strands are worked on by the DNA pol IIIs.

Question

Quizplus · Accepted Answer

DNA pol I is responsible for replacing RNA primers with DNA, which only needs to be done on the lagging strand. In contrast, DNA pol III is responsible for the majority of replication on both the leading and lagging strands. Therefore, only one molecule of DNA pol I is needed compared to two molecules of DNA pol III in a prokaryotic replisome.

A Prokaryotic Replisome Typically Contains Two Molecules of DNA Pol