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Nucleotide Excision Repair
Nucleotide excision repair is a DNA repair mechanism. DNA damage occurs constantly because of chemicals (e.g. Intercalation (biochemistry), intercalating agents), radiation and other mutagens. Three excision repair pathways exist to repair single stranded DNA damage: Nucleotide excision repair (NER), base excision repair (BER), and DNA mismatch repair (MMR). While the BER pathway can recognize Base excision repair#Lesions processed by BER, specific non-bulky lesions in DNA, it can correct only damaged bases that are removed by Base excision repair#DNA glycosylases, specific glycosylases. Similarly, the MMR pathway only targets mismatched Watson-Crick base pairs. Nucleotide excision repair (NER) is a particularly important excision mechanism that removes DNA damage induced by ultraviolet light (UV). UV DNA damage results in bulky DNA adducts — these adducts are mostly thymine dimers and 6,4-photoproducts. Recognition of the damage leads to removal of a short single-stranded DNA s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide Excision Repair-journal
Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all Life, life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common Nutrient, nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a pentose, five-carbon sugar (ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine, and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP), and uridine triph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryotes
The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of life forms alongside the two groups of prokaryotes: the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but given their generally much larger size, their collective global biomass is much larger than that of prokaryotes. The eukaryotes emerged within the archaeal kingdom Promethearchaeati and its sole phylum Promethearchaeota. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among the Archaea. Eukaryotes first emerged during the Paleoproterozoic, likely as flagellated cells. The leading evolutionary theory is they were created by symbiogenesis between an anaerobic Promethearchaeati archaean and an aerobic proteobacterium, which form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide Excision Repair
Nucleotide excision repair is a DNA repair mechanism. DNA damage occurs constantly because of chemicals (e.g. Intercalation (biochemistry), intercalating agents), radiation and other mutagens. Three excision repair pathways exist to repair single stranded DNA damage: Nucleotide excision repair (NER), base excision repair (BER), and DNA mismatch repair (MMR). While the BER pathway can recognize Base excision repair#Lesions processed by BER, specific non-bulky lesions in DNA, it can correct only damaged bases that are removed by Base excision repair#DNA glycosylases, specific glycosylases. Similarly, the MMR pathway only targets mismatched Watson-Crick base pairs. Nucleotide excision repair (NER) is a particularly important excision mechanism that removes DNA damage induced by ultraviolet light (UV). UV DNA damage results in bulky DNA adducts — these adducts are mostly thymine dimers and 6,4-photoproducts. Recognition of the damage leads to removal of a short single-stranded DNA s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAD23B
UV excision repair protein RAD23 homolog B is a protein that in humans is encoded by the ''RAD23B'' gene. Function The protein encoded by this gene is one of two human homologs of Saccharomyces cerevisiae Rad23, a protein involved in nucleotide excision repair (NER). This protein was found to be a component of the protein complex that specifically complements the NER defect of xeroderma pigmentosum group C (XP-c) cell extracts in vitro. This protein was also shown to interact with, and elevate the nucleotide excision activity of 3-methyladenine-DNA glycosylase (MPG), which suggested a role in DNA damage recognition in base excision repair. This protein contains an N-terminal ubiquitin-like domain, which was reported to interact with 26S proteasome, and thus this protein may be involved in the ubiquitin mediated proteolytic pathway in cells. Role in DNA repair The complex of XPC-RAD23B is the initial damage recognition factor in global genomic nucleotide excision repair (GG-NE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAD23A
UV excision repair protein RAD23 homolog A is a protein that in humans is encoded by the ''RAD23A'' gene. Function The protein encoded by this gene is one of two human homologs of ''Saccharomyces cerevisiae'' Rad23, a protein involved in nucleotide excision repair (NER). This protein was shown to interact with, and elevate the nucleotide excision activity of 3-methyladenine-DNA glycosylase (MPG), which suggested a role in DNA damage recognition in base excision repair. This protein contains an N-terminal ubiquitin-like domain, which was reported to interact with 26S proteasome, as well as with ubiquitin protein ligase E6AP, and thus suggests that this protein may be involved in the ubiquitin mediated proteolytic pathway in cells. RAD23A interacts with Y-family DNA polymerase iota (ι), DNA polymerase eta (η), DNA polymerase kappa and Y family DNA polymerase REV1. These polymerases have roles in the DNA damage tolerance pathway of translesion synthesis that allows the re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Replication Protein A
Replication protein A (RPA) is the major protein that binds to single-stranded DNA (ssDNA) in eukaryotic cells. In vitro, RPA shows a much higher affinity for ssDNA than RNA or double-stranded DNA. RPA is required in replication, recombination and repair processes such as nucleotide excision repair and homologous recombination. It also plays roles in responding to damaged DNA. Structure RPA is a heterotrimer, composed of the subunits RPA1 (RPA70) (70kDa subunit), RPA2 (RPA32) (32kDa subunit) and RPA3 (RPA14) (14kDa subunit). The three RPA subunits contain six OB-folds (oligonucleotide/oligosaccharide binding), with DNA-binding domains (DBD) designated DBDs A-F, that bind RPA to single-stranded DNA. DBDs A, B, C and F are located on RPA1, DBD D is located on RPA2, and DBD E is located on RPA3. DBDs C, D, and E make up the trimerization core of the protein with flexible linker regions connecting them all together. Due to these flexible linker regions RPA is consider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ERCC1
DNA excision repair protein ERCC-1 is a protein that in humans is encoded by the ''ERCC1'' gene. Together with ERCC4, ERCC1 forms the ERCC1-XPF enzyme complex that participates in DNA repair and DNA recombination. Many aspects of these two gene products are described together here because they are partners during DNA repair. The ERCC1-XPF nuclease is an essential activity in the pathway of DNA nucleotide excision repair (NER). The ERCC1-XPF nuclease also functions in pathways to repair double-strand breaks in DNA, and in the repair of “crosslink” damage that harmfully links the two DNA strands. Cells with disabling mutations in ''ERCC1'' are more sensitive than normal to particular DNA damaging agents, including ultraviolet (UV) radiation and to chemicals that cause crosslinking between DNA strands. Genetically engineered mice with disabling mutations in ERCC1 have defects in DNA repair, accompanied by metabolic stress-induced changes in physiology that result in prematur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ERCC6
DNA excision repair protein ERCC-6 (also CS-B protein) is a protein that in humans is encoded by the ''ERCC6'' gene. The ''ERCC6'' gene is located on the long arm of chromosome 10 at position 11.23.NIH. "ERCC6 Gene." Genetics Home Reference. National Institutes of Health, 16 Feb. 2015. Web. 22 Feb. 2015. . Having 1 or more copies of a mutated ERCC6 causes Cockayne syndrome, type II. Function DNA can be damaged by ultraviolet radiation, toxins, radioactive substances, and reactive biochemical intermediates like free radicals. The ERCC6 protein is involved in repairing the genome when specific genes undergoing transcription (dubbed ''active genes'') are inoperative; as such, ERCC6 serves as a transcription-coupled excision repair protein, being one of the fundamental enzymes in active gene repair. Structure and Mechanism CSB has been found to exhibit ATPase properties; there are contradictory publications regarding the effect of ATP concentration on CSB's activity. The most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ERCC8
DNA excision repair protein ERCC-8 is a protein that in humans is encoded by the ''ERCC8'' gene. This gene encodes a WD repeat protein, which interacts with the Cockayne syndrome type B (CSB) and p44 proteins, the latter being a subunit of the RNA polymerase II transcription factor II H. Mutations in this gene have been identified in patients with the hereditary disease Cockayne syndrome (CS). CS is an accelerated aging disorder characterized by photosensitivity, impaired development and multi-system progressive degeneration. The CS cells are abnormally sensitive to ultraviolet radiation and are defective in the repair of transcriptionally active genes. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. CS arises from germline mutations in either of two genes ''CSA(ERCC8)'' or ''CSB(ERCC6)''. ''CSA'' mutations generally give rise to a more moderate form of CS than ''CSB'' mutations. Mutations in the ''CSA'' gene accoun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XPG-Nterminus
In molecular biology the protein domain XPG refers to, in this case, the N-terminus of XPG. The XPG protein can be corrected by a 133 kDa nuclear protein, XPGC. XPGC is an acidic protein that confers normal ultraviolet (UV) light resistance. It is a magnesium-dependent, single-strand DNA endonuclease that makes structure-specific endonucleolytic incisions in a DNA substrate containing a duplex region and single-stranded arms. XPGC cleaves one strand of the duplex at the border with the single-stranded region. Homology XPG belongs to a family of proteins that includes: * RAD2 from ''Saccharomyces cerevisiae'' (Baker's yeast) and rad13 from ''Schizosaccharomyces pombe'' (Fission yeast), which are single-stranded DNA endonucleases,; * mouse and human FEN-1, a structure-specific endonuclease; * RAD2 from fission yeast and RAD27 from budding yeast; * fission yeast exo1, a 5' -3' double-stranded DNA exonuclease that may act in a pathway that corrects mismatched base pairs; * yeast DHS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XPE (DDB2)
DNA damage-binding protein 1 is a protein that in humans is encoded by the ''DDB1'' gene. Gene The gene's position is on chromosome 11q12-q13. Protein The DDB1 gene encodes the large subunit of DNA damage-binding protein, a heterodimer composed of a large and a small (DDB2) subunit. DDB1 contains 1140 amino acids, amounting to a mass of 127 kDa. Function As its name suggests, DDB1 was initially implicated in the process of a specific type of DNA repair known as nucleotide excision repair. Since then, researchers have found that DDB1 primarily functions as a core component of the CUL4A- and CUL4B-based E3 ubiquitin ligase complexes. DDB1 serves as a bridge or adaptor protein which interacts with dozens of proteins known as DDB1 and CUL4-associated factors (DCAFs). These DCAFs are often ubiquitin ligase substrates and regulate numerous essential processes in the cell including DNA repair (DDB2), DNA replication, chromatin remodeling ( Cdt2) and more. Interactions DDB1 has been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XPC (gene)
Xeroderma pigmentosum, complementation group C, also known as XPC, is a protein which in humans is encoded by the ''XPC'' gene. XPC is involved in the recognition of bulky DNA adducts in nucleotide excision repair. It is located on chromosome 3. Function This gene encodes a component of the nucleotide excision repair (NER) pathway. There are multiple components involved in the NER pathway, including Xeroderma pigmentosum (XP) A-G and V, Cockayne syndrome (CS) A and B, and trichothiodystrophy (TTD) group A, etc. This component, XPC, plays an important role in the early steps of global genome NER, especially in damage recognition, open complex formation, and repair protein complex formation. The complex of XPC-RAD23B is the initial damage recognition factor in global genomic nucleotide excision repair (GG-NER). XPC-RAD23B recognizes a wide variety of lesions that thermodynamically destabilize DNA duplexes, including UV-induced photoproducts (cyclopyrimidine dimers and 6-4 photo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
