Which one of the following statements about the DNA polymerase III of E. coli is NOT correct?
GATE Life Sciences - 2022,
Answer: A
The statement that is NOT correct is it catalyzes nick translation.
Nick translation needs a 5′ → 3′ exonuclease working ahead of the polymerase, removing nucleotides from the 5′ end at a nick while new ones are added at the 3′ end. That combination belongs to DNA polymerase I, which uses it to remove RNA primers. DNA polymerase III has no 5′ → 3′ exonuclease.
The other statements are true of polymerase III. It is the main replicative enzyme, so losing it is lethal. It copies a single-stranded template into a complementary strand, extending a primer. Its ε subunit carries 3′ → 5′ exonuclease activity, which proofreads misincorporated bases.
Please log in or register to report this question.