delta DNA polymerase complex
Definition
Target type: cellularcomponent
A multimeric DNA polymerase enzyme complex which differs in composition amongst species; in humans it is a heterotetramer of four subunits of approximately 125, 50, 68 and 12kDa, while in S. cerevisiae, it has three different subunits which form a heterotrimer, and the active enzyme is a dimer of this heterotrimer. Functions in DNA replication, mismatch repair and excision repair. [GOC:jl, ISBN:0198547684, PMID:11205330, PMID:12403614]
The delta DNA polymerase complex is a crucial enzyme complex involved in DNA replication and repair. It is a multi-subunit complex that comprises several proteins:
**1. POLδ:** This is the catalytic subunit of the complex, responsible for the actual DNA polymerase activity. It possesses 5'-3' polymerase and 3'-5' exonuclease activities. The exonuclease activity is essential for proofreading newly synthesized DNA and ensuring its fidelity.
**2. PCNA (Proliferating Cell Nuclear Antigen):** PCNA acts as a processivity factor, encircling the DNA and allowing POLδ to extend DNA strands much longer than it could on its own. It forms a ring around the DNA, functioning as a sliding clamp.
**3. Replication Factor C (RFC):** RFC is a clamp loader protein complex that helps PCNA associate with DNA. It loads PCNA onto the DNA, which is required for efficient DNA synthesis.
**4. The 9-1-1 checkpoint clamp:** This checkpoint clamp complex is involved in DNA damage response pathways. It senses stalled or damaged replication forks and activates a cellular response, leading to cell cycle arrest and DNA repair.
**5. Other accessory proteins:** Other proteins can also associate with the delta DNA polymerase complex, including:
* **DNA ligase:** This enzyme joins DNA fragments together.
* **RNase H2:** This enzyme removes RNA primers from Okazaki fragments.
* **Replication factor A (RPA):** This single-stranded DNA binding protein stabilizes the single-stranded DNA that is being replicated.
The precise composition and structure of the delta DNA polymerase complex can vary depending on the organism and the specific cellular context. However, the core components described above are essential for its function. This complex plays a critical role in DNA replication and repair, ensuring the fidelity of genetic information during cell division and maintaining genomic integrity.'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| DNA polymerase delta catalytic subunit | A DNA polymerase delta catalytic subunit that is encoded in the genome of human. [PRO:DNx, UniProtKB:P28340] | Homo sapiens (human) |
Compounds (8)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| foscarnet | Foscarnet: An antiviral agent used in the treatment of cytomegalovirus retinitis. Foscarnet also shows activity against human herpesviruses and HIV. phosphonoformic acid : Phosphoric acid in which one of the hydroxy groups is replaced by a carboxylic acid group. It is used as the trisodium salt as an antiviral agent in the treatment of cytomegalovirus retinitis (CMV retinitis, an inflamation of the retina that can lead to blindness) and as an alternative to ganciclovir for AIDS patients who require concurrent antiretroviral therapy but are unable to tolerate ganciclovir due to haematological toxicity. | carboxylic acid; one-carbon compound; phosphonic acids | antiviral drug; geroprotector; HIV-1 reverse transcriptase inhibitor; sodium-dependent Pi-transporter inhibitor |
| ochracin | ochracin: produced by Aspergillus alutaceus; structure in first source | isochromanes | |
| zidovudine 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 |
| pnu183792 | PNU183792: structure in first source | ||
| pecilocin | pecilocin: fungicidal antibiotic produced by Paecilomyces varioti Bainier var. antibioticus; structure | N-acylpyrrolidine | |
| sch 725680 | Sch 725680: an aazaphilone from Aspergillus sp.; structure in first source | ||
| pinophilin b | pinophilin B: from cultures of a fungus (Penicillium pinophilum Hedgcok) derived from a seaweed; structure in first source |