Crossover junction endodeoxyribonuclease
| Crossover junction endodeoxyribonuclease | |||||||||
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| Identifiers | |||||||||
ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
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Crossover junction endodeoxyribonuclease, also known as Holliday junction resolvase, Holliday junction endonuclease, Holliday junction-cleaving endonuclease, Holliday junction-resolving endoribonuclease, crossover junction endoribonuclease, and cruciform-cutting endonuclease, is an enzyme involved in DNA repair and homologous recombination. Specifically, it performs endonucleolytic cleavage that results in single-stranded crossover between two homologous DNA molecules at the Holliday junction to produce recombinant DNA products for chromosomal segregation. This process is known as Holliday junction resolution.
Biological Function
The
are all crossover junction endodeoxyribonucleases that perform Holliday Junction resolution. Holliday junction resolution catalyzed by crossover junction endodeoxyribonuclease is shown in the figure below.
Crossover junction endodeoxyribonucleases also play key roles in DNA repair. During cell growth and meiosis, DNA double-strand breaks (DSBs) often occur, and are usually repaired by homologous recombination.[5] Because Crossover junction endodeoxyribonucleases perform Holliday Junction resolution, a crucial step of homologous recombination, they are therefore involved in repair of DSBs.
Structure
A figure of Thermus thermophilus RuvC in complex with a Holliday junction is shown below.
Mechanism
These enzymes are highly selective for branched DNA, although
Human Relevance
After a 20-year search, in 2008, a human crossover junction endodeoxyribonuclease, GEN1, was finally identified [13] . GEN1 performs similar functions and operates by similar mechanisms as previously studied Crossover junction endodeoxyribonuclease in bacteria, archaea, and other eukarya.[13] The enzyme is thought to play a role in
References
External links
- Crossover+junction+endodeoxyribonuclease at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
