What is Ku70 80?
The Ku70/80 heterodimer is a key-player in the NHEJ pathway and binds to DNA termini with high affinity, where it helps to protect DNA ends from degradation and to recruit other NHEJ factors required for repair.
What do KU proteins do?
Ku is a dimeric protein complex that binds to DNA double-strand break ends and is required for the non-homologous end joining (NHEJ) pathway of DNA repair. Ku is evolutionarily conserved from bacteria to humans. The ancestral bacterial Ku is a homodimer (two copies of the same protein bound to each other).
How does non-homologous end joining work?
Non-homologous end joining (NHEJ) is a pathway that repairs double-strand breaks in DNA. NHEJ is referred to as “non-homologous” because the break ends are directly ligated without the need for a homologous template, in contrast to homology directed repair, which requires a homologous sequence to guide repair.
What is Ku70 and Ku80?
The Ku heterodimer (Ku70/Ku80) is a main component of the nonhomologous end-joining (NHEJ) pathway that repairs DNA double-strand breaks (DSBs). Ku binds the broken DNA end and recruits other proteins to facilitate the processing and ligation of the broken end.
What does Artemis do Immunology?
The Artemis complex is a protein complex that functions in V(D)J recombination, the somatic recombination process which generates diversity in T cell receptors and immunoglobulins.
What is Ku heterodimer?
In eukaryotes, Ku is a heterodimer comprised of two subunits, Ku70 and Ku80, that is best characterized for its central role as the initial DNA end binding factor in the “classical” non-homologous end joining (C-NHEJ) pathway, the main DNA double-strand break (DSB) repair pathway in mammals.
What is the difference between homologous and non-homologous chromosomes?
The primary difference between these two chromosomes – homologous and non-homologous lies in their constituency of alleles. Homologous chromosomes consist of alleles of the same gene type found in the same loci unlike non-homologous chromosomes, which constitute alleles of varying gene types.
What is the difference between non-homologous end joining and homology directed repair?
HDR is a precise repair mechanism that uses homologous donor DNA to repair DNA damage, whereas NHEJ is an error-prone mechanism in which broken ends of DNA are joined together, often resulting in a heterogeneous pool of insertions and deletions.
What is Homeo locus chromosome?
Homologous chromosomes are made up of chromosome pairs of approximately the same length, centromere position, and staining pattern, for genes with the same corresponding loci. One homologous chromosome is inherited from the organism’s mother; the other is inherited from the organism’s father.
What does the RAD51 gene do?
The RAD51 gene provides instructions for making a protein that is essential for repairing damaged DNA. Breaks in DNA can be caused by natural and medical radiation or other environmental exposures, and also occur when chromosomes exchange genetic material in preparation for cell division.
What protein does RAD51 code for?
DNA repair protein RAD51 homolog 1 is a protein encoded by the gene RAD51. The enzyme encoded by this gene is a member of the RAD51 protein family which assists in repair of DNA double strand breaks. RAD51 family members are homologous to the bacterial RecA, Archaeal RadA and yeast Rad51.
What is the function of Ku70?
Alan G. Goodman, in International Review of Cell and Molecular Biology, 2019 Ku70 is a DNA repair subunit protein that binds to DNA double-strand break ends and helps repair DNA via the non-homologous end-joining (NHEJ) pathway (Mimori et al., 1986 ).
How does the Ku70–Ku80 heterodimer bind to DNA?
NHEJ is initiated by the avid ability of the Ku70–Ku80 (Ku) heterodimer, to bind double-stranded (ds) DNA ends. Structural analysis of Ku has revealed a basket-shaped molecule with a core that allows threading onto a dsDNA ends without sequence specificity, making contact with the DNA backbone but not bases (Walker, Corpina, & Goldberg, 2001 ).
Does the Ku70 gene play a role in longevity assurance?
These results suggest that reduced ability to repair DNA double-strand breaks causes early aging, and that the wild-type Ku70 gene plays an important role in longevity assurance. (Also see DNA damage theory of aging .)
Where are the Ku70 and Ku80 subunits?
The Ku70 subunit is located proximal to the DNA end, and Ku80 is located toward internal DNA nucleotides [51]. The crystal structure thus reveals a preformed ring structure that fits well with the specific DNA ends recognition properties of Ku.