DNA-directed DNA polymerase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1); the synthesis of DNA from deoxyribonucleotide triphosphates in the presence of a DNA template and a 3'hydroxyl group. [EC:2.7.7.7, GOC:vw, ISBN:0198547684]

DNA-directed DNA polymerase activity is a fundamental enzymatic process that underlies DNA replication and repair. DNA polymerases catalyze the synthesis of new DNA strands by adding nucleotides to a pre-existing DNA template strand. The process involves the following steps:

1. **Template Binding:** The DNA polymerase binds to the template DNA strand, which serves as a guide for the synthesis of the new strand.
2. **Primer Recognition:** The polymerase recognizes and binds to a short primer strand of RNA or DNA that has already been synthesized and annealed to the template. This primer provides a free 3'-hydroxyl group to which the polymerase can add nucleotides.
3. **Nucleotide Selection and Incorporation:** The polymerase selects and incorporates the correct nucleotide based on the complementary base pairing rules. Each incoming nucleotide must pair with its complementary base on the template strand (adenine with thymine, guanine with cytosine).
4. **Phosphate Transfer:** The polymerase catalyzes the formation of a phosphodiester bond between the 3'-hydroxyl group of the primer and the 5'-phosphate group of the incoming nucleotide, adding the new nucleotide to the growing DNA chain.
5. **Translocation:** After each nucleotide is added, the polymerase moves along the template strand in a process called translocation, preparing for the addition of the next nucleotide.

DNA polymerases are essential for maintaining genetic integrity and ensuring the faithful transmission of genetic information during cell division. They play critical roles in various cellular processes, including:

* **DNA Replication:** DNA polymerases synthesize new DNA strands during replication, ensuring the duplication of the entire genome before cell division.
* **DNA Repair:** DNA polymerases are involved in repairing damaged DNA, correcting errors that may occur during replication or due to environmental damage.
* **Recombination:** DNA polymerases participate in genetic recombination, a process that shuffles genetic information and contributes to genetic diversity.

Mutations in DNA polymerases can lead to various genetic disorders, including cancer, immune deficiencies, and developmental abnormalities. Understanding the molecular function of DNA-directed DNA polymerase activity is crucial for unraveling the mechanisms of DNA replication and repair, and for developing therapeutic strategies for treating diseases related to DNA polymerase dysfunction.'
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Proteins (17)

Compounds (39)