page_title: Crossover junction endodeoxyribonuclease
section_title: Biological Function
hierarchical_section_title: Crossover junction endodeoxyribonuclease / Biological Function
caption_attribution_description: English: HJ resolvase function
context_page_description: 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.
context_section_description: The Holliday junction is a structure that forms during genetic recombination, and links two double-stranded DNA molecules with a single-stranded crossover, which form during mitotic and meiotic recombination. Crossover junction endodeoxyribonucleases catalyze Holiday junction resolution, which is the formation of separate recombinant DNA molecules and chromosomal separation after the crossover event at the Holliday junction. Crossover junction endodeoxyribonucleases with Holliday Junction resolution function have been identified in all three domains of life - bacteria, archaea, and eukarya. RuvC in bacteria, CCE1 in Saccharomyces cerevisiae, and GEN1 in humans   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. Because Crossover junction endodeoxyribonucleases perform Holliday Junction resolution, a crucial step of homologous recombination, they are therefore involved in repair of DSBs.
caption: Holliday junction resolution catalyzed by crossover junction endodeoxyribonuclease. Left: First, four strands of DNA (two black and two white) combine to form two double stranded DNA molecules at a Holliday junction. Center: Next, substrate form a complex with crossover junction endodeoxyribonuclease complex for Holliday junction resolution. Right: Finally, completion of Holliday Junction Resolution results in recombinant DNA. Diagram generated based on Wyatt et. al.[4]
exif: {}