Question

Which of the following is not a function of APE1?

(a) 5’->3’ exonuclease

(b) Generating nick at 5’ end

(c) Generating abasic site

(d) Improving fidelity of pol beta

This question was addressed to me in an international level competition.

My enquiry is from Repair of DNA Damage: MMR, BER in division DNA Mutation, DNA Repair, Transposable Elements of Cytogenetics

Answer 1

The correct choice is (c) Generating abasic site

Explanation: While APE1 has a 5’-> 3’ exonuclease activity, it is not a bifunctional glycosylase and can’t generate an abasic site.