| DNA nucleotidyltransferases | <enzyme> A general term denoting enzymes that catalyze the template-directed incorporation of deoxyribonucleotides into a DNA chain. Registry number: EC 2.7.7.- (12 Dec 1998) |
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| DNA photolyase | <enzyme, molecular biology> A DNA repair enzyme which recognises and removes dimers that have formed between pyrimidine nitrogenous bases on the same strand as each other, as a result of too much ultraviolet radiation. The enzyme can only do this if visible light is present. (09 Oct 1997) |
| DNA, plant | Deoxyribonucleic acid that makes up the genetic material of plants. (12 Dec 1998) |
| DNA polymerase | <enzyme, molecular biology> Enzymes involved in template directed synthesis of DNA from deoxyribonucleotide triphosphates. I, II and III are known in E. Coli, III appears to be most important in genome replication and I is important for its ability to edit out unpaired bases at the end of growing strands. Animal cells have and polymerases, with apparently responsible for replication of nuclear DNA and for replication of mitochondrial. All these function with a DNA strand as template. Retroviruses possess a unique DNA polymerase (reverse transcriptase) that uses an RNA template. (18 Nov 1997) |
| DNA polymerase beta | <enzyme> A DNA repair enzyme that catalyses DNA synthesis during base excision DNA repair. Registry number: EC 2.7.7.- (12 Dec 1998) |
| DNA polymerase i | DNA Polymerase I is an enzyme that aids in DNA replication. It has the following 3 functions: 1. Polymerizes in the 5(r) to 3(r) direction on single-stranded template. 2. Degrades single or double-stranded DNA from a free 3(r)-OH end, and 3. Degrades double-stranded DNA from a free 5(r) end. (09 Oct 1997) |
| DNA polymerase II | <enzyme> An enzyme that aids in DNA replication. It has a number of different functions, including the repair of ultraviolet radiation damaged DNA. (09 Oct 1997) |
| DNA polymerase III | <enzyme> An enzyme that aids in DNA replication. It has a number of different functions, such as: proofreading newly replicated DNA, removing nucleotides from the 3' end of the strand one by one, and binding nucleotides from the 5' end of the strand. (09 Oct 1997) |
| DNA polymerisation | <molecular biology> The making of a DNA molecule from nucleotide monomers by linking them together in a long chain (a polymer). (09 Oct 1997) |
| DNA polymorphism | A condition in which one of two different but normal nucleotide sequences can exist at a particular site in DNA. (05 Mar 2000) |
| DNA primase | <enzyme> A single-stranded DNA-dependent RNA polymerase that functions to initiate, or prime, DNA synthesis by synthesizing a nucleotide RNA polymer. Registry number: EC 2.7.7.- (12 Dec 1998) |
| DNA primers | Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques. (12 Dec 1998) |
| DNA probe | <molecular biology> A small piece of nucleic acid that has been labelled with a radioactive isotope, dye, or enzyme and is used to locate a complementary nucleotide sequence or gene on a DNA molecule. (14 Nov 1997) |
| DNA probes | Species- or subspecies-specific DNA (including complementary DNA (DNA, complementary), conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridises with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32p and 125i and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections. (12 Dec 1998) |
| DNA probes, HLA | DNA probes specific for the human leukocyte antigen genes, which represent the major histocompatibility determinants in humans. The four known loci are designated as a, b, c, and d. Specific antigens are identified by a locus notation and number, e.g., HLA-a11. The inheritance of certain HLA alleles is associated with increased risk for certain diseases (e.g., insulin-dependent diabetes mellitus). (12 Dec 1998) |