Question

Choose the correct option-

DNA polymerase III of E.coli is -
1.required for de novo synthesis of new strands of DNA
2.involved in the repair of damaged DNA
3.required to restart a replication fork
4. involved in DNA recombination​

Answer 1

Answer:

The key difference between DNA polymerase 1 2 and 3 mainly relies on the prime function of each enzyme. DNA polymerase 3 is the main enzyme which catalyzes the DNA synthesis, while DNADNA polymerase I (pol I) processes RNA primers during lagging-strand synthesis and fills small gaps during DNA repair reactions. polymerase 1 and 2 are involved in DNA repairing and proofreading

The DNA polymerase III holoenzyme is a complex, multisubunit enzyme that is responsible for the synthesis of most of the Escherichia coli chromosome. ... Tau causes the polymerase to dimerize, perhaps forming a structure that can coordinate leading and lagging strand synthesis at the replication fork. Two molecules of DNA polymerase III bind to the primers on the leading and lagging strands and synthesize new DNA from the 3′ hydroxyls (Fig. 4.5). DNA polymerase cannot synthesize new DNA without a pre-existing 3′-OH. Thus, DNA replication requires an RNA primer to initiate strand formation.In Escherichia coli, five DNA polymerases have been found and designated as DNA polymerase I–V, in order of their discovery. The main function of the third polymerase, Pol III, is duplication of the chromosomal DNA, while other DNA polymerases are involved mostly in DNA repair and translesion DNA synthesis.DNA polymerase III of E.coli is -

1.required for de novo synthesis of new strands of DNA

2.involved in the repair of damaged DNA

3.required to restart a replication fork

4. involved in DNA recombination