Direct double-strand breaks in DNA have been implicated in cellular lethality of the antitumor antibiotic neocarzinostatin, but the mechanism of their formation has not been elucidated. Evidence is presented that neocarzinostatin causes sequence-specific direct double-strand breaks whose formation is strongly influenced by the activating thiol. Seven-fold more double-strand breaks result when g...

Deinococcus radiodurans R1 (DEIRA) a member of Deinococcae family can survive ~12 kGy dose of γ radiation which can generate about 200 double strands and 3000 single strand breaks per genome. An efficient DNA strand break repair, contributes maximum to the radioresistance of Deinococcus radiodurans. Distinction in DNA strand break repair from others seems to lie in the mechanism of action of DN...

Targeted genome engineering requires nucleases that introduce a highly specific double-strand break in the genome that is either processed by homology-directed repair in the presence of a homologous repair template or by non-homologous end-joining (NHEJ) that usually results in insertions or deletions. The error-prone NHEJ can be efficiently suppressed by 'nickases' that produce a single-strand...

The mechanism of DNA strand break induction due to K-shell photoabsorption of DNA constituent phosphorus was studied by computer simulation. Photon induced Auger process in DNA solution was modeled and introduced to the Monte Carlo simulation code DBREAK, which allows the estimation of DNA strand break production on pBR322 plasmid DNA in aqueous solution. The simulation was carried out for the ...

Human DNA polymerase and DNA ligase utilization for the repair of a major class of ionizing radiation-induced DNA lesion [DNA single-strand breaks containing 3'-phosphoglycolate (3'-PG)] was examined using a novel, chemically defined vector substrate containing a single, site-specific 3'-PG single-strand break lesion. In addition, the major human AP endonuclease, HAP1 (also known as APE1, APEX,...