Ku protein: Difference between revisions
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<StructureSection load='1JEY' size='475' side='right' caption='Structure of the Ku heterodimer bound to DNA (PDB entry [[1JEY]])' scene=''> | <StructureSection load='1JEY' size='475' side='right' caption='Structure of the Ku heterodimer bound to DNA (PDB entry [[1JEY]])' scene=''> | ||
== Overview == | == Overview == | ||
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 | 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 | ||
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'''Crystal structure of Ku Heterodimer unbound to DNA''' <ref> PMID: 11493912</ref> | '''Crystal structure of Ku Heterodimer unbound to DNA''' <ref> PMID: 11493912</ref> | ||
== Structure == | == Structure == | ||
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=== α/β-Domain === | |||
Contained inside the <scene name='56/567269/Ku70_dimer/2'>α/β-Domain</scene> is a [[Rossman fold]] at the N terminus that is used to bind nucleotides in <scene name='56/567269/Bound_dna/3'>DNA</scene> <ref> PMID: 11493912</ref>. In terms of protein structure, the <scene name='56/567269/Ku70_dimer/2'>α/β-Domain</scene> contributes little to the dimer interface between the subunits. The C terminus of the domain can be bound to other repair molecules, using <scene name='56/567269/Ku70_dimer/2'>α/β-Domain</scene> as a scaffold <ref> PMID: 11493912</ref>. | Contained inside the <scene name='56/567269/Ku70_dimer/2'>α/β-Domain</scene> is a [[Rossman fold]] at the N terminus that is used to bind nucleotides in <scene name='56/567269/Bound_dna/3'>DNA</scene> <ref> PMID: 11493912</ref>. In terms of protein structure, the <scene name='56/567269/Ku70_dimer/2'>α/β-Domain</scene> contributes little to the dimer interface between the subunits. The C terminus of the domain can be bound to other repair molecules, using <scene name='56/567269/Ku70_dimer/2'>α/β-Domain</scene> as a scaffold <ref> PMID: 11493912</ref>. | ||
=== β-barrel === | === β-barrel === | ||
The <scene name='56/567269/Ku70_dimer/4'>β-barrel</scene> is the main source of interactions of the <scene name='56/567269/Ku_heterodimer/3'>Ku heterodimer</scene> itself and <scene name='56/567269/Bound_dna/3'>DNA helix</scene>, with each <scene name='56/567269/Ku70_dimer/4'>β-barrel</scene> being composed of seven β strands with the majority in antiparallel arrangement <ref> PMID: 11493912</ref>. The quantity of the strands lends the structures to be symmetrical. Both <scene name='56/567269/Ku70_dimer/4'>β-barrels</scene> in the dimer form the base of the cradle by fitting in the grooves of <scene name='56/567269/Bound_dna/3'>DNA</scene>. | The <scene name='56/567269/Ku70_dimer/4'>β-barrel</scene> is the main source of interactions of the <scene name='56/567269/Ku_heterodimer/3'>Ku heterodimer</scene> itself and <scene name='56/567269/Bound_dna/3'>DNA helix</scene>, with each <scene name='56/567269/Ku70_dimer/4'>β-barrel</scene> being composed of seven β strands with the majority in antiparallel arrangement <ref> PMID: 11493912</ref>. The quantity of the strands lends the structures to be symmetrical. Both <scene name='56/567269/Ku70_dimer/4'>β-barrels</scene> in the dimer form the base of the cradle by fitting in the grooves of <scene name='56/567269/Bound_dna/3'>DNA</scene>. | ||
=== C-terminal arm === | === C-terminal arm === | ||
The <scene name='56/567269/Ku70_dimer/7'>C-terminal arm</scene> is an α-helical domain that associates with the β-barrel of the opposite subunit, with the arm stretching across the <scene name='56/567269/Bound_dna/3'>DNA helix</scene> <ref> PMID: 11493912</ref>. As a result, the <scene name='56/567269/Ku70_dimer/7'>C-terminal arm</scene> strengthens the cradle composed of the two β-barrels. | The <scene name='56/567269/Ku70_dimer/7'>C-terminal arm</scene> is an α-helical domain that associates with the β-barrel of the opposite subunit, with the arm stretching across the <scene name='56/567269/Bound_dna/3'>DNA helix</scene> <ref> PMID: 11493912</ref>. As a result, the <scene name='56/567269/Ku70_dimer/7'>C-terminal arm</scene> strengthens the cradle composed of the two β-barrels. | ||
=== DNA binding ring === | === DNA binding ring === | ||
The DNA binding ring on the open end of DNA is associated with the <scene name='56/567269/Ku70_subunit/3'>Ku70 subunit</scene>. By binding <scene name='56/567269/Bound_dna/3'>DNA</scene>, Ku realigns the the strands and protects the molecule from degradation and unwanted bonds while NHEJ occurs <ref> PMID: 11493912</ref>. The regulation of the DNA binding ring of Ku is still under research, with data supporting oxidative stress and redox reactions decreasing the association of the <scene name='56/567269/Ku_heterodimer/3'>Ku heterodimer</scene> with <scene name='56/567269/Bound_dna/3'>DNA</scene> through alterations in cysteine residues on the <scene name='56/567269/Ku70_subunit/3'>Ku70 subunit</scene> (NEED SOURCE 3 and 4, NEED SCENE OF CYSTEINES). | The <scene name='56/567269/Ku70_dimer/6'>DNA binding ring</scene> on the open end of DNA is associated with the <scene name='56/567269/Ku70_subunit/3'>Ku70 subunit</scene>. By binding <scene name='56/567269/Bound_dna/3'>DNA</scene>, Ku realigns the the strands and protects the molecule from degradation and unwanted bonds while NHEJ occurs <ref> PMID: 11493912</ref>. The regulation of the DNA binding ring of Ku is still under research, with data supporting oxidative stress and redox reactions decreasing the association of the <scene name='56/567269/Ku_heterodimer/3'>Ku heterodimer</scene> with <scene name='56/567269/Bound_dna/3'>DNA</scene> through alterations in cysteine residues on the <scene name='56/567269/Ku70_subunit/3'>Ku70 subunit</scene> (NEED SOURCE 3 and 4, NEED SCENE OF CYSTEINES). | ||
== Function == | == Function == | ||
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</StructureSection> | |||
== References== | == References== | ||
<references /> | <references /> | ||