Question

Which aspect of the E. coli DNA replication machinery accounts for high processivity?

a. The beta sliding clamp of DNA Polymerase III

b. 3’-5’ exonuclease activity of DNA Polymerase I

c. 5’-3’ exonuclease activity of DNA Polymerase I

d. Single strand DNA binding protein (SSB)

e. The core subunit of DNA Polymerase III

An explanation of the solution would be greatly appreciated, thanks!

Answer 1

In E. coli, which replicates its entire genome from a single replication fork, the polymerase DNA Pol III is the enzyme primarily responsible for DNA replication and forms a replication complex with extremely high processivity.
DNA clamp proteins are integral components of the DNA replication machinery and serve to increase the processivity of their associated polymerases.
Hence, option, "a" is the correct answer.