Ku protein: Difference between revisions

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Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Terry Nowell, Peter A. Duden, Michal Harel, Jaime Prilusky

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 == Overview ==
-The <scene name='56/567269/Ku_heterodimer/3'>Ku heterodimer</scene> (<scene name='56/567269/Ku70_subunit/3'>Ku70</scene> and <scene name='56/567269/Ku80_subunit/3'>Ku80</scene> subunits) contributes to genomic integrity through its ability to bind DNA double-strand breaks and facilitate repair by the non-homologous end-joining pathway. The crystal structure of the human Ku heterodimer was determined both alone and bound to a 55-nucleotide <scene name='56/567269/Bound_dna/3'>DNA</scene> element at 2.7 and 2.5 A resolution, respectively. Ku70 and Ku80 share a common topology and form a dyad-symmetrical molecule with a preformed ring that encircles duplex DNA. The binding site can cradle two full turns of DNA while encircling only the central 3-4 base pairs (bp). Ku makes no contacts with DNA bases and few with the sugar-phosphate backbone, but it fits sterically to major and minor groove contours so as to position the DNA helix in a defined path through the protein ring. These features seem well designed to structurally support broken DNA ends and to bring the DNA helix into phase across the junction during end processing and ligation. <ref> PMID: 11493912</ref>
+The '''Ku protein''' binds to the ends of double-strand breaks and it is required in DNA-repair for non-homologous end joining. The eukaryotic Ku protein is a
+<scene name='56/567269/Ku_heterodimer/3'>heterodimer</scene>
+composed of a
+<scene name='56/567269/Ku70_subunit/3'>Ku70 subunit</scene>
+and a <scene name='56/567269/Ku80_subunit/3'>Ku80 subunit</scene>
+. This contributes to genomic integrity through its ability to bind DNA double-strand breaks and facilitate repair by the non-homologous end-joining pathway. The crystal structure of the human Ku heterodimer was determined both alone and
+<scene name='56/567269/Bound_dna/3'>bound to a 55-nucleotide DNA</scene>
+element at 2.7 and 2.5 A resolution, respectively. Ku70 and Ku80 share a common topology and form a dyad-symmetrical molecule with a preformed ring that encircles duplex DNA. The binding site can cradle two full turns of DNA while encircling only the central 3-4 base pairs (bp). Ku makes no contacts with DNA bases and few with the sugar-phosphate backbone, but it fits sterically to major and minor groove contours so as to position the DNA helix in a defined path through the protein ring. These features seem well designed to structurally support broken DNA ends and to bring the DNA helix into phase across the junction during end processing and ligation. <ref> PMID: 11493912</ref>
 [[Image:1jeq.jpg]]