scholarly journals Identification of Two Domains of the p70 Ku Protein Mediating Dimerization with p80 and DNA Binding

1998 ◽  
Vol 273 (2) ◽  
pp. 842-848 ◽  
Author(s):  
Jingsong Wang ◽  
Xingwen Dong ◽  
Kyungjae Myung ◽  
Eric A. Hendrickson ◽  
Westley H. Reeves
Keyword(s):  
Dna Binding ◽  
Ku Protein

scholarly journals Reduced sulphydryl groups are required for DNA binding of Ku protein

1993 ◽  
Vol 293 (3) ◽  
pp. 769-774 ◽  
Author(s):  
W W Zhang ◽  
M Yaneva
Keyword(s):  
Dna Binding ◽  
Protein A ◽  
Binding Activity ◽  
Heat Inactivation ◽  
Cysteine Residues ◽  
Dna Binding Activity ◽  
Sulphydryl Groups ◽  
Ku Protein

The Ku protein, a DNA-binding complex that is composed of two subunits of 70 kDa and of 86 kDa, has been suggested to play a role in gene transcription. The dependence of the in vitro DNA-binding activity of affinity-purified Ku protein on reduced cysteine residues has been studied using sulphydryl-modifying agents. Inhibition of the DNA-binding activity was caused by alkylation with N-ethylmaleimide and by crosslinking with azadicarboxylic acid bis(dimethylamide). Treatment of the protein with a large excess of N-ethylmaleimide after it had bound to DNA did not completely dissociate the complex from the DNA, suggesting that some cysteines may be in direct contact with DNA. Pre-incubation of the protein at 37 degrees C or above caused rapid inactivation of DNA binding. The elevated temperature azadicarboxylic acid bis(dimethylamide) treatments resulted in the formation of a crosslinked product, which was detected by Western blotting. The effects of azadicarboxylic acid bis(dimethylmaleimide) and heat were completely reversible by treatment with a reducing agent, such as dithiothreitol. These results demonstrate that in vitro DNA-binding activity of the Ku protein requires reduced sulphydryl groups. Interestingly, the DNA-binding activity of Ku protein was protected from heat inactivation by the presence of a HeLa cell nuclear extract, suggesting that a nuclear factor or factors may be responsible for the maintenance of the reduced cysteines of the Ku protein in vivo. Thus, the biochemical function of the Ku protein may be regulated through oxidation-reduction of its cysteine residues.

Effect of age on DNA binding of the ku protein in irradiated human peripheral blood mononuclear cells (PBMC)

1999 ◽  
Vol 34 (5) ◽  
pp. 645-658 ◽  
Author(s):  
Daniela Frasca ◽  
Paola Barattini ◽  
Donatella Tirindelli ◽  
Luisa Guidi ◽  
Carlo Bartoloni ◽  
...  
Keyword(s):  
Dna Binding ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells ◽  
Ku Protein ◽  
Effect Of Age

scholarly journals C-terminal low-complexity sequence repeats of Mycobacterium smegmatis Ku modulate DNA binding

2013 ◽  
Vol 33 (1) ◽  
Author(s):  
Ambuj K. Kushwaha ◽  
Anne Grove
Keyword(s):  
Dna Binding ◽  
Mycobacterium Smegmatis ◽  
Low Complexity ◽  
Strand Break ◽  
End Joining ◽  
Stem Loop ◽  
T4 Dna Ligase ◽  
Ku Protein ◽  
Non Homologous End Joining ◽  
Dna Ends

Ku protein is an integral component of the NHEJ (non-homologous end-joining) pathway of DSB (double-strand break) repair. Both eukaryotic and prokaryotic Ku homologues have been characterized and shown to bind DNA ends. A unique feature of Mycobacterium smegmatis Ku is its basic C-terminal tail that contains several lysine-rich low-complexity PAKKA repeats that are absent from homologues encoded by obligate parasitic mycobacteria. Such PAKKA repeats are also characteristic of mycobacterial Hlp (histone-like protein) for which they have been shown to confer the ability to appose DNA ends. Unexpectedly, removal of the lysine-rich extension enhances DNA-binding affinity, but an interaction between DNA and the PAKKA repeats is indicated by the observation that only full-length Ku forms multiple complexes with a short stem-loop-containing DNA previously designed to accommodate only one Ku dimer. The C-terminal extension promotes DNA end-joining by T4 DNA ligase, suggesting that the PAKKA repeats also contribute to efficient end-joining. We suggest that low-complexity lysine-rich sequences have evolved repeatedly to modulate the function of unrelated DNA-binding proteins.

Water soluble palladium(ii) and platinum(ii) acyclic diaminocarbene complexes: solution behavior, DNA binding, and antiproliferative activity

2020 ◽  
Vol 44 (15) ◽  
pp. 5762-5773 ◽  
Author(s):  
Tatiyana V. Serebryanskaya ◽  
Mikhail A. Kinzhalov ◽  
Vladimir Bakulev ◽  
Georgii Alekseev ◽  
Anastasiya Andreeva ◽  
...  
Keyword(s):  
Dna Binding ◽  
Antiproliferative Activity ◽  
Water Soluble ◽  
Solution Behavior ◽  
Antitumor Potential ◽  
Acyclic Diaminocarbene

Water soluble Pd(ii) and Pt(ii)–ADC species synthesized via the metal-mediated coupling of isocyanides and 1,2-diaminobenzene have demonstrated antitumor potential.

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