Target type: cellularcomponent
A DNA polymerase complex consisting of a large subunit, responsible for the catalytic activities, and a small accessory subunit. Functions in the replication and repair of mitochondrial DNA. [GOC:jl, PMID:12045093]
The gamma DNA polymerase complex is a multi-protein assembly responsible for replicating mitochondrial DNA. This complex is essential for maintaining the integrity of the mitochondrial genome and ensuring proper cellular function. It consists of several key components, each playing a crucial role in the replication process:
* **POLG:** The catalytic subunit of the complex, also known as DNA polymerase gamma, is a bifunctional enzyme possessing both polymerase and 3'-5' exonuclease activity. POLG is responsible for synthesizing new DNA strands using the existing mitochondrial DNA template.
* **POLG2:** The accessory subunit, also known as mitochondrial DNA polymerase gamma accessory subunit, is a protein that binds to POLG and enhances its activity. POLG2 facilitates efficient DNA replication by enhancing the processivity of POLG, allowing it to synthesize longer stretches of DNA without dissociating from the template.
* **TFAM:** Mitochondrial transcription factor A, a DNA-binding protein, plays a crucial role in regulating mitochondrial DNA transcription. TFAM interacts with the gamma DNA polymerase complex, facilitating the assembly of the replication machinery at the origin of replication.
* **SSBP1:** Single-stranded DNA-binding protein 1 is a protein that binds to single-stranded DNA, preventing the formation of secondary structures and promoting the efficient progression of the replication fork. SSBP1 interacts with the gamma DNA polymerase complex, facilitating the unwinding of the DNA helix and providing access for the polymerase to the template strand.
* **Other accessory proteins:** In addition to the core components mentioned above, several other proteins are known to associate with the gamma DNA polymerase complex and contribute to its function. These include the mitochondrial single-stranded DNA binding protein (mtSSB), the mitochondrial helicase Twinkle, and the mitochondrial DNA ligase (LIG3).
The interaction of these components within the gamma DNA polymerase complex ensures precise and efficient replication of mitochondrial DNA, maintaining the integrity of this essential organelle and supporting cellular function.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| DNA polymerase subunit gamma-1 | A DNA polymerase subunit gamma-1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P54098] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| TTP | pyrimidine ribonucleoside 5'-triphosphate | ||
| aphidicolin | aphidicolin : A tetracyclic diterpenoid that has an tetradecahydro-8,11a-methanocyclohepta[a]naphthalene skeleton with two hydroxymethyl substituents at positions 4 and 9, two methyl substituents at positions 4 and 11b and two hydroxy substituents at positions 3 and 9. An antibiotic with antiviral and antimitotical properties. Aphidicolin is a reversible inhibitor of eukaryotic nuclear DNA replication. Aphidicolin: An antiviral antibiotic produced by Cephalosporium aphidicola and other fungi. It inhibits the growth of eukaryotic cells and certain animal viruses by selectively inhibiting the cellular replication of DNA polymerase II or the viral-induced DNA polymerases. The drug may be useful for controlling excessive cell proliferation in patients with cancer, psoriasis or other dermatitis with little or no adverse effect upon non-multiplying cells. | tetracyclic diterpenoid | antimicrobial agent; antimitotic; antineoplastic agent; antiviral drug; apoptosis inducer; Aspergillus metabolite; DNA synthesis inhibitor; EC 2.7.7.7 (DNA-directed DNA polymerase) inhibitor; fungal metabolite |
| deoxyguanosine triphosphate | deoxyguanosine phosphate; guanyl deoxyribonucleotide; purine 2'-deoxyribonucleoside 5'-triphosphate | Arabidopsis thaliana metabolite; Escherichia coli metabolite; human metabolite; mouse metabolite; plant metabolite; Saccharomyces cerevisiae metabolite | |
| acyclovir triphosphate |