Question

E. Coli dna polymerase i possesses which activities?

Answer 1

i) 3´-5´ exonuclease activity

ii) 5´-3´ exonuclease activity

iii) 5´-3 polymerase activity

Explanation:

There are total five DNA polymerases found in E. coli.

DNA Polymerase I enzyme :

1. DNA Polymerase I possesses a 3´-5´ exonuclease activity also known as "proofreading" activity, which remove incorrectly paired bases which are mistakenly paired during DNA replication by DNA pol III.

2. DNA Polymerase I also contains a 5´- 3´ exonuclease activity, which enables it to replace mismatched nucleotides in the growing strand of DNA.

4. It also removes primers from the lagging strand and finally these okazaki fragments are joined by ligase enzyme.