BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Because of its 5′ to 3′ exonuclease activity, DNA polymerase I removes RNA primers and fills the gaps between Okazaki fragments with DNA.

Detailed explanation-2: -The DNA polymerase I is an example of DNA polymerase that has a specific activity. It has an exonuclease activity that proofreads the new DNA strand for mismatched base pairing during DNA replication. It can also remove the RNA primers in the DNA synthesis.

Detailed explanation-3: -DNA polymerase I of eubacteria functions in vivo to synthesize short stretches of DNA during excision repair and to remove RNA primers and fill the gaps between Okazaki fragments in lagging strand replication.

Detailed explanation-4: -Primase synthesizes RNA primers complementary to the DNA strand. DNA polymerase III extends the primers, adding on to the 3’ end, to make the bulk of the new DNA. RNA primers are removed and replaced with DNA by DNA polymerase I.

Detailed explanation-5: -Thus, the 3’—-5’ exonuclease of the Drosophila DNA polymerase-primase participates in exonucleolytic proofreading by excising noncomplementary nucleotides prior to extension of the primer by polymerase action.