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DNA Polymerase Delta
DNA polymerase delta (DNA Pol δ) is an enzyme complex found in eukaryotes that is involved in DNA replication and repair. The DNA polymerase delta complex consists of 4 subunits: POLD1, POLD2, POLD3, and POLD4. DNA Pol δ is an enzyme used for both leading and lagging strand synthesis. It exhibits increased processivity when interacting with the proliferating cell nuclear antigen (PCNA). As well, the multisubunit protein replication factor C The replication factor C, or RFC, is a five-subunit protein complex that is required for DNA replication. The subunits of this heteropentamer are named Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 in ''Saccharomyces cerevisiae''. RFC is used in eukaryotic re ..., through its role as the clamp loader for PCNA (which involves catalysing the loading of PCNA on to DNA) is important for DNA Pol δ function. References External links * EC 2.7.7 DNA replication DNA repair DNA-binding proteins {{2.7-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryote
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). Euka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the most essential part for biological inheritance. This is essential for cell division during growth and repair of damaged tissues, while it also ensures that each of the new cells receives its own copy of the DNA. The cell possesses the distinctive property of division, which makes replication of DNA essential. DNA is made up of a double helix of two complementary strands. The double helix describes the appearance of a double-stranded DNA which is thus composed of two linear strands that run opposite to each other and twist together to form. During replication, these strands are separated. Each strand of the original DNA molecule then serves as a template for the production of its counterpart, a process referred to as semiconservative replication. As a result of semi-conservative rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Repair
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA damage, resulting in tens of thousands of individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages (interstrand crosslinks or ICLs). This can eventually lead to malignant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POLD1
The gene polymerase delta 1 (''POLD1'') encodes the large, POLD1/p125, catalytic subunit of the DNA polymerase delta (Polδ) complex. The Polδ enzyme is responsible for synthesizing the lagging strand of DNA, and has also been implicated in some activities at the leading strand (Figure 1). The POLD1/p125 subunit encodes both DNA polymerizing and exonuclease domains, which provide the protein an important second function in proofreading to ensure replication accuracy during DNA synthesis, and in a number of types of replication-linked DNA repair following DNA damage. Germline mutations impairing activity of POLD1 have been implicated in several types of hereditary cancer, in some sporadic cancers, and in a developmental syndrome of premature aging, Mandibular hypoplasia, Deafness, and Progeroid features and Lipodystrophy (MDPL/ MDP syndrome). Studies of POLD1 emphasize the importance of maintaining genomic stability to limit tumorigenesis. It is currently unclear whether the en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POLD2
DNA polymerase delta subunit 2 is an enzyme that in humans is encoded by the ''POLD2'' gene. It is a component of the DNA polymerase delta complex. Interactions POLD2 has been shown to Protein-protein interaction, interact with PCNA. References Further reading * * * * * * * * * * * * * * * External links * {{gene-7-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POLD3
DNA polymerase delta subunit 3 is an enzyme that in humans is encoded by the ''POLD3'' gene. It is a component of the DNA polymerase delta complex. Interactions POLD3 has been shown to interact with PCNA Proliferating cell nuclear antigen (PCNA) is a DNA clamp that acts as a processivity factor for DNA polymerase δ in eukaryotic cells and is essential for replication. PCNA is a homotrimer and achieves its processivity by encircling the DNA, whe .... References Further reading * * * * * * * * * * {{gene-11-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POLD4
DNA polymerase delta subunit 4, also known as DNA polymerase delta subunit p12, is a protein that in humans is encoded by the ''POLD4'' gene. It is a component of the DNA polymerase delta DNA polymerase delta (DNA Pol δ) is an enzyme complex found in eukaryotes that is involved in DNA replication and repair. The DNA polymerase delta complex consists of 4 subunits: POLD1, POLD2, POLD3, and POLD4. DNA Pol δ is an enzyme used fo ... complex. References Further reading * * * * * * * * * * * {{gene-11-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCNA
Proliferating cell nuclear antigen (PCNA) is a DNA clamp that acts as a processivity factor for DNA polymerase δ in eukaryotic cells and is essential for replication. PCNA is a homotrimer and achieves its processivity by encircling the DNA, where it acts as a scaffold to recruit proteins involved in DNA replication, DNA repair, chromatin remodeling and epigenetics. Many proteins interact with PCNA via the two known PCNA-interacting motifs PCNA-interacting peptide (PIP) box and AlkB homologue 2 PCNA interacting motif (APIM). Proteins binding to PCNA via the PIP-box are mainly involved in DNA replication whereas proteins binding to PCNA via APIM are mainly important in the context of genotoxic stress. Function The protein encoded by this gene is found in the nucleus and is a cofactor of DNA polymerase delta. The encoded protein acts as a homotrimer and helps increase the processivity of leading strand synthesis during DNA replication. In response to DNA damage, this protein is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Replication Factor C
The replication factor C, or RFC, is a five-subunit protein complex that is required for DNA replication. The subunits of this heteropentamer are named Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 in ''Saccharomyces cerevisiae''. RFC is used in eukaryotic replication as a clamp loader, similar to the γ Complex in ''Escherichia coli''. Its role as a clamp loader involves catalyzing the loading of PCNA onto DNA. It binds to the 3' end of the DNA and uses ATP to open the ring of PCNA so that it can encircle the DNA. ATP hydrolysis causes the release of RFC, with concomitant clamp loading onto DNA. For DNA polymerase, RFC serves as primer identification. RFC plays an important role in the proliferation, invasion, and progression of various malignant tumors. RFC acts as a tumor suppressor gene. RFC sub-units The 5 subunits of replication factor C are 1.RFC1 40KDa 2.RFC2 0KDa 3.RFC3 8KDa 4.RFC4 7KDaref name=":0"> 5.RFC5 6KDa Eukaryotes, yeast, mice, drosophila, calf thymus, humans, rice, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
