Summarize and compare the properties of DNA polymerase I, II, and III.

Verified step by step guidance

1. Start by identifying the primary function of each DNA polymerase enzyme in prokaryotes, focusing on DNA polymerase I, II, and III.
2. Describe DNA polymerase I, emphasizing its role in removing RNA primers through its 5' to 3' exonuclease activity and filling in the resulting gaps with DNA.
3. Explain DNA polymerase II, noting its function mainly in DNA repair and its 3' to 5' exonuclease proofreading activity to maintain DNA fidelity.
4. Detail DNA polymerase III as the main enzyme responsible for the bulk of DNA synthesis during replication, highlighting its high processivity and 3' to 5' exonuclease proofreading activity.
5. Compare the enzymes by summarizing their exonuclease activities, roles in replication versus repair, and their relative importance in the DNA replication process.

Key Concepts

DNA Polymerase I

DNA Polymerase I is primarily involved in DNA repair and the removal of RNA primers during replication. It has 5' to 3' polymerase activity, 3' to 5' exonuclease proofreading, and unique 5' to 3' exonuclease activity that removes RNA primers, allowing replacement with DNA.

DNA Polymerase II

DNA Polymerase II functions mainly in DNA repair and replication restart after damage. It possesses 5' to 3' polymerase and 3' to 5' exonuclease proofreading activities but lacks 5' to 3' exonuclease activity, making it less involved in primer removal.

DNA Polymerase III

DNA Polymerase III is the primary enzyme responsible for bacterial DNA replication. It has high processivity and 5' to 3' polymerase activity, along with 3' to 5' exonuclease proofreading, but lacks 5' to 3' exonuclease activity, so it cannot remove RNA primers.