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2',5'-Oligoadenylate Synthetase definition: An enzyme that catalyzes the conversion of ATP into a series of (2'-5') linked oligoadenylates and pyrophosphate in the presence of double-stranded RNA. These oligonucleotides activate an endoribonuclease (RNase L) which cleaves single-stranded RNA. Interferons can act as inducers of these reactions. EC 2.7.7.-.
DNA Polymerase I definition: A DNA-dependent DNA polymerase characterized in prokaryotes and may be present in higher organisms. It has both 3'-5' and 5'-3' exonuclease activity, but cannot use native double-stranded DNA as template-primer. It is not inhibited by sulfhydryl reagents and is active in both DNA synthesis and repair. EC 2.7.7.7.
DNA Polymerase Alpha definition: An enzyme that plays major roles in DNA metabolism. The protein, which exhibits bidirectional nuclease activity is required for both DNA synthesis and repair. DNA polymerase alpha is most active in dividing cells, and is primarily involved with lagging strand synthesis.
DNA Polymerase II definition: A DNA-dependent DNA polymerase characterized in E. coli and other lower organisms. It may be present in higher organisms and has an intrinsic molecular activity only 5% of that of DNA Polymerase I. This polymerase has 3'-5' exonuclease activity, is effective only on duplex DNA with gaps or single-strand ends of less than 100 nucleotides as template, and is inhibited by sulfhydryl reagents. EC 2.7.7.7.
DNA Polymerase III definition: A DNA-dependent DNA polymerase characterized in E. coli and other lower organisms but may be present in higher organisms. Use also for a more complex form of DNA polymerase III designated as DNA polymerase III* or pol III* which is 15 times more active biologically than DNA polymerase I in the synthesis of DNA. This polymerase has both 3'-5' and 5'-3' exonuclease activities, is inhibited by sulfhydryl reagents, and has the same template-primer dependence as pol II. EC 2.7.7.7.
DNA Polymerase Delta definition: An enzyme that has dual functionality in DNA synthesis. The protein has the ability to facilitate DNA synthesis by polymerase action and an exonucleolytic activity that degrades single stranded DNA in the 3' to 5' direction. This protein is essential for leading strand synthesis.
DNA-Directed DNA Polymerase definition: DNA-dependent DNA polymerases found in bacteria, animal and plant cells. During the replication process, these enzymes catalyze the addition of deoxyribonucleotide residues to the end of a DNA strand in the presence of DNA as template-primer. They also possess exonuclease activity and therefore function in DNA repair. EC 2.7.7.7.
DNA Polymerase definition: Nucleotidyltransferases that catalyze the addition of deoxyribonucleotide residues to the end of a DNA. EC 2.7.7.7 or EC 2.7.7.49
DNA-directed DNA Polymerase definition: Catalyses DNA-template-directed extension of the 3'- end of a DNA strand by one nucleotide at a time. Cannot initiate a chain de novo. Requires a primer, which may be DNA or RNA. (IUBMB Enzyme Nomenclature)
Polynucleotide Adenylyltransferase definition: An enzyme that catalyzes the synthesis of polyadenylic acid from ATP. May be due to the action of RNA polymerase (EC 2.7.7.6) or polynucleotide adenylyltransferase (EC 2.7.7.19). EC 2.7.7.19.
Riboadenylate Transferase definition: Nuclear or cytoplasmic human Riboadenylate Transferases (Poly A Polymerase Family) catalyze template-independent post-transcriptional extension of the 3 prime end of an RNA strand by nonspecific and CPSF/AAUAAA-dependent polyadenylation activity during eukaryotic mRNA maturation. The N-terminal region appears required for nonspecific polymerase activity, while the N- and C-termini are required for specific polymerase activity. Specificity may occur through C-terminus interaction with CPSF, regulated by phosphorylation. The poly(A) reaction involves endoribonucleolytic pre-RNA cleavage at the poly(A) site and synthesis of the poly(A) tail. (NCI)
Poly(ADP Ribose) Polymerase definition: The human protein poly(ADP ribose) polymerase protein (1013aa, ~113 kDa) is encoded by the PARP1 gene (PARP1). Poly(ADP ribose) polymerase (PARP) is a cytosolic protein, and when activated is cleaved into two fragments of 89kd and 24kd. The enzyme modifies various nuclear proteins by poly(ADP-rybosyl)ation. The protein is involved in the regulation of various important cellular processes such as differentiation, proliferation, tumor transformation, and recovery from DNA damage. Its inhibition has been studied in cancerous cells and degenerative diseases to demonstrate how apoptosis can be inhibited when the PARP is inactive or absent.
Poly(ADP-ribose) Polymerases definition: Enzymes that catalyze the transfer of multiple ADP-RIBOSE groups from nicotinamide-adenine dinucleotide (NAD) onto protein targets, thus building up a linear or branched homopolymer of repeating ADP-ribose units i.e., POLY ADENOSINE DIPHOSPHATE RIBOSE.
RNA Polymerase I definition: A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. The enzyme functions in the nucleolar structure and transcribes DNA into RNA. It has different requirements for cations and salts than RNA polymerase II and III and is not inhibited by alpha-amanitin. EC 2.7.7.6.
RNA Polymerase II definition: A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. EC 2.7.7.6.
RNA Polymerase III definition: A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure where it transcribes DNA into RNA. It has specific requirements for cations and salt and has shown an intermediate sensitivity to alpha-amanitin in comparison to RNA polymerase I and II. EC 2.7.7.6.
DNA-Directed RNA Polymerases definition: Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).
RNA Polymerase definition: RNA polymerases comprise a group of enzymes that catalyze extension, one nucleotide at a time, of the 3 prime-end of an RNA strand along a complementary DNA template.
DNA-directed RNA Polymerase definition: Enzymes that catalyze the template-directed stepwise addition of ribonucleotides to the 3' end of a growing RNA chain using a single-stranded DNA template. The reaction is important in the flow of information from DNA to proteins. Three different forms of the polymerase have been identified and characterized.
Taq Polymerase definition: A heat stable DNA-DIRECTED DNA POLYMERASE from the bacteria Thermus aquaticus. It is widely used for the amplification of genes through the process of POLYMERASE CHAIN REACTION. EC 2.7.7.-.
Taq Polymerase definition: A heat stable DNA-directed DNA polymerase. The enzyme is widely utilized in laboratory polymerase chain reaction applications.
DNA Polymerase beta definition: A DNA repair enzyme that catalyzes DNA synthesis during base excision DNA repair. EC 2.7.7.7.
DNA Polymerase Beta definition: Human DNA polymerase beta protein (334 aa 38 kDa) is encoded by the human DNA polymerase beta (POLB) gene. This monomer protein is a DNA repair enzyme that catalyzes "gap-filling" DNA synthesis in a stepwise, distributive manner during base excision repair. This enzyme is required for DNA maintenance, replication, recombination, and drug resistance.
delta DNA polymerase complex definition: 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]
DNA polymerase complex definition: A protein complex that possesses DNA polymerase activity and is involved in template directed synthesis of DNA. [GOC:jl, http://cancerweb.ncl.ac.uk/, PMID:12045093]
Polymerase definition: Encoded by Polymerase Genes, Polymerase enzymes catalyze polymerization reactions, especially of nucleotides to polynucleotides. (NCI)
Polymerase Gene definition: Polymerase Genes encode enzymes (Polymerases) that catalyze polymerization reactions, especially of nucleotides to polynucleotides. (NCI)
DNA polymerase activity definition: Catalysis of the reaction: deoxynucleoside triphosphate + DNA(n) = diphosphate + DNA(n+1); the synthesis of DNA from deoxyribonucleotide triphosphates in the presence of a nucleic acid template and primer. [EC:2.7.7.7, GOC:mah]
DNA polymerase binding definition: Interacting selectively with a DNA polymerase. [GOC:mah]