| Type: | Family | Name: | Ku80 |
| Description: | This group consists of eukaryotic proteins containing the Ku80 domain. In eukaryotes it has been shown that Ku protein is involved in repairing DNA double-strand breaks by non-homologous end-joining [, , ]. Ku is a heterodimer of approximately 70kDa and 80 kDa subunits []. Both these subunits have strong sequence similarity and ithas been suggested that they may have evolved by gene duplication from a homodimeric ancestor in eukaryotes []. The prokaryotic Ku members are homodimers and they have been predicted to beinvolved in the DNA repair system, which is mechanistically similar to the eukaryotic non-homologous end joining [, ]. Recent findings have implicated yeast Ku in telomericstructure maintenance in addition to non-homologous end-joining []. Some of thephenotypes of Ku-knockout mice may indicate a similar role for Ku at mammalian telomeres [].Evolutionary notes: With the currently available phyletic information it is difficult to determine the correct evolutionary trajectory of the Ku domain. It is possible that the core Ku domain waspresent in bacteria and archaea even before the presence of the eukaryotes. Eukaryotes might have vertically inherited the Ku-core protein from a common ancestor shared with a certain archaeal lineage or throughhorizontal transfer from bacteria. Alternatively, the core Ku domain could have evolved in the eukaryotic lineage and then horizontally transferred to the prokaryotes. Sequencing of additional archaeal genomes andthose of early-branching eukaryotes may help resolve the evolutionary history of the Ku domain.Structure notes: The eukaryotic Ku heterodimer is comprised of an alpha/beta N-terminal domain, a central beta-barreldomain and a helical C-terminal arm []. Structural analysis of the Ku70/80 heterodimerbound to DNA indicates that subunit contacts lead to the formation of a highly charged channel through which the DNA passes without making any contacts with the DNA bases [].For additional information please see []. | Short Name: | Ku80 |
| GO Term | Gene Name |
|---|---|
| GO:0003677 | IPR024193 |
| GO:0003684 | IPR024193 |
| GO:0042162 | IPR024193 |
| GO:0000723 | IPR024193 |
| GO:0006303 | IPR024193 |
| GO:0006310 | IPR024193 |
| GO:0005634 | IPR024193 |
| GO:0043564 | IPR024193 |
| GO Term | Gene Name |
|---|---|
| GO:0003677 | IPR024193 |
| GO:0003684 | IPR024193 |
| GO:0042162 | IPR024193 |
| GO:0000723 | IPR024193 |
| GO:0006303 | IPR024193 |
| GO:0006310 | IPR024193 |
| GO:0005634 | IPR024193 |
| GO:0043564 | IPR024193 |
