| DNA-protein interaction | <molecular biology> Any complex that forms between a protein molecule and DNA. Examples are nucleosomes (structures formed for the purpose of DNA storage) and any gene regulatory protein (a protein which regulates transcription by binding to a regulatory region on the DNA). (09 Oct 1997) |
|---|---|
| DNA, protozoan | Deoxyribonucleic acid that makes up the genetic material of protozoa. (12 Dec 1998) |
| DNA puff | <molecular biology> An area on a chromosome where transcription of DNA into mRNA, or replication of DNA is occurring, resulting in an enlarged, puffy appearance of the area. Similar to chromosome puff, except generalised to any type of chromosome in any type of organism. (09 Oct 1997) |
| DNA rearrangement | <molecular biology> Wholesale movement of sequences from one position to another in DNA, such as occur somatically, for example in the generation of antibody diversity. (18 Nov 1997) |
| DNA, recombinant | Biologically active DNA which has been formed by the in vitro joining of segments of DNA from different sources. It includes the recombination joint or edge of a heteroduplex region where two recombining DNA molecules are connected. (12 Dec 1998) |
| DNA renaturation | <molecular biology> The reformation of double stranded DNA from thermally denatured DNA. The rate of reassociation depends upon the degree of repetition and is slowest for unique sequences (this is the basis of the Cot value). (18 Nov 1997) |
| DNA repair | <molecular biology> Each cell has a series of special enzymes to correct the errors in DNA structure and sequence. This protects genetic information against environmental damage and replication errors and restore the DNA to its original state. (25 Jun 1999) |
| DNA repair gene | A gene engaged in DNA repair. When a DNA repair gene is altered, mutations pile up throughout the DNA. (12 Dec 1998) |
| DNA repair pathway | The sequence of steps in the repair of DNA. Each step is governed by an enzyme. (12 Dec 1998) |
| DNA, repetitive | DNA sequences that are repeated in the genome. (12 Dec 1998) |
| DNA replicase | <enzyme> An aspect of EC 2.7.7.7; mouse enzyme has both DNA polymerase and DNA primase activity Registry number: EC 2.7.7.- (26 Jun 1999) |
| DNA replication | <molecular biology> The process whereby a copy of a DNA molecule is made and thus the genetic information it contains is duplicated. The parental double stranded DNA molecule is replicated semi conservatively, i.e. Each copy contains one of the original strands paired with a newly synthesised strand that is complementary in terms of at and GC base pairing. Though in this sense conceptually simple, mechanistically a complex process involving a number of enzymes. (18 Nov 1997) |
| DNA restriction enzymes | <enzyme> Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of dnas, and have made it possible to splice and recombine genes from one organism into the genome of another. Registry number: EC 3.1.21 (12 Dec 1998) |
| DNA restriction-modification enzymes | Systems consisting of two enzymes, a modification methylase and a restriction endonuclease. They are closely related in their specificity and protect the DNA of a given bacterial species. The methylase adds methyl groups to adenine or cytosine residues in the same target sequence that constitutes the restriction enzyme binding site. The methylation renders the target site resistant to restriction, thereby protecting DNA against cleavage. (12 Dec 1998) |
| DNA reverse gyrase | <enzyme> A topoisomerase II subclass which introduces positive superhelical turns into DNA Registry number: EC 3.1.- Synonym: reverse gyrase (26 Jun 1999) |