Is Pol I Necessary for Base Excision Repair?

Biology
Thread starter hidemi
Start date Mar 1, 2021
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Base

In summary, Pol I, or DNA Polymerase I, is an enzyme that plays a crucial role in Base Excision Repair (BER). It recognizes damaged bases with its unique structure and replaces them with new nucleotides. While other DNA polymerases can participate in BER, Pol I is the most active. It also contributes to the accuracy of BER through its proofreading function. Pol I is also involved in other DNA repair mechanisms, but its role in those is not as well understood.

Mar 1, 2021

hidemi

Homework Statement: Which process does NOT require the 5' to 3' exonuclease activity of Pol I in E. coli?
A) joining of Okazaki fragments
B)nucleotide-excision repair
C)base-excision repair
D)nick translation
E)All of these require the 5′ to 3′ exonuclease activity of Pol I.

Ans: (B)

Relevant Equations: none

I think (C) should be one of the answers too.
I think that base-excision repair does not need the 5' to 3' exonuclease activity of Pol I, either. Am I right?

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Mar 1, 2021

Asim Riaz

Yes, you are correct. Base-excision repair does not require the 5' to 3' exonuclease activity of Pol I.

1. What is Pol I and what is its role in base excision repair?

Pol I, also known as DNA polymerase I, is an enzyme that plays a crucial role in base excision repair. It is responsible for filling in the gaps left after damaged or incorrect bases are removed from DNA strands.

2. How does base excision repair work without Pol I?

While Pol I is the main enzyme involved in base excision repair, there are other polymerases that can also carry out the repair process. For example, Pol beta and Pol delta can also fill in gaps left by damaged bases.

3. Are there any negative consequences if Pol I is not present during base excision repair?

Yes, if Pol I is absent or not functioning properly, it can lead to an accumulation of DNA damage and mutations. This can have serious consequences, such as increased risk of cancer or other genetic disorders.

4. Can Pol I be replaced by other enzymes in base excision repair?

While Pol I is the main enzyme involved in base excision repair, it can be replaced by other polymerases in certain situations. For example, if Pol I is mutated or not present, Pol beta or Pol delta can take over its role in filling in gaps left by damaged bases.

5. Is Pol I necessary for all types of base excision repair?

No, Pol I is not necessary for all types of base excision repair. It is primarily involved in the repair of single-base lesions, while other polymerases may be involved in repairing larger lesions or multiple base damage.