A Holliday junction is a mobile junction between four strands of DNA. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known The structure is named after Robin Holliday, who proposed it in 1964[1][2] to account for a particular type of exchange of genetic information in yeast known as homologous recombination. Robin Holliday proposed a mechanism of DNA-strand exchange that attempted to explain gene-conversion events that occur during meiosis in fungi Yeasts are a growth form of eukaryotic Microorganisms classified in the kingdom Fungi, with about 1500 Species currently described Homologous recombination is a type of Genetic recombination, a process of physical rearrangement occurring between two strands of DNA.
Because these junctions are between homologous sequences they can slide up and down the DNA. In bacteria, this sliding (or branch migration) is facilitated by the RuvABC complex or RecG protein, molecular motors that use the energy of ATP hydrolysis to push the junction around. The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have RuvABC is a complex of three Proteins that mediate Branch migration and resolve the Holliday junction created during Recombination repair. Adenosine-5'-triphosphate ( ATP) is a multifunctional Nucleotide that is most important as a " molecular currency" of intracellular Energy The junction must then be resolved, split up, to restore 2 linear duplexes. This can be done to either restore the parental configuration or to establish a crossed over configuration. Resolution can occur in either a horizontal or vertical fashion during homologous recombination, giving patch products (if in same orientation during double strand break repair) or splice products (if in different orientations during double strand break repair).
Holliday junctions are important in maintaining genomic integrity.
See also
References
- ^ Liu Y, West S (2004). Genetic recombination is the process by which a strand of genetic material (usually DNA; but can also be RNA) is broken and then joined to a different DNA molecule "Happy Hollidays: 40th anniversary of the Holliday junction". Nat Rev Mol Cell Biol 5 (11): 937–44. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document. PMID 15520813.
- ^ Hays FA, Watson J, Ho PS (2003). "Caution! DNA Crossing: Crystal Structures of Holliday Junctions". J Biol Chem 278 (50): 49663–49666. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
External links
- MeSH Holliday+junctions
- Conformational Change of Holliday Junction
- Holliday Structure in tetrahedral form
- Analysis of branch migration activities of proteins using synthetic DNA substrates (a protocol)
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