On the lagging strand, the primer on an Okazaki fragment is removed by the '---exonuclease activity of DNA polymerase I. What enzyme replaces the degraded primer with deoxyribonucleotides?

Question

On the lagging strand, the primer on an Okazaki fragment is removed by the '--->exonuclease activity of DNA polymerase I. What enzyme replaces the degraded primer with deoxyribonucleotides?

Quizplus · Accepted Answer

DNA polymerase I not only has exonuclease activity but also has the ability to add new nucleotides to the 3' end of a growing strand. After removing the RNA primer, DNA polymerase I fills in the gap with deoxyribonucleotides, essentially replacing the degraded primer with DNA.

On the Lagging Strand, the Primer on an Okazaki Fragment