Biological consequences of strand breaks in plasmid and viral DNA.
Some biological consequences of strand breakage in biologically active single- and double-stranded plasmid and viral DNA are examined. A double-strand break in DNA produced by restriction-endonucleases in aqueous solution is not a 100% lethal damage. The survival depends strongly on the structure of the end groups. Evidence is presented that survival is the result of a balance between degradation and repair. The enzymatically produced double-strand break (dsb) is a potentially lethal damage similar to the irradiation-produced dsb in cells. Results with double-stranded biologically active DNA treated either with gamma-rays, heat, pancrease nuclease or UV-light in aqueous solution suggest that a single-strand damage is also a potentially lethal damage. Mechanisms for conversion of single-strand damage to lethal events are discussed.
Schulte-Frohlinde
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Max-Planck-Institut für Strahlenchemie, Mülheim a. d. Ruhr, West Germany.
D004249:DNA Damage; D004260:DNA Repair; D004277:DNA, Single-Stranded / Q000528:radiation effects; D004279:DNA, Viral / Q000528:radiation effects; D010957:Plasmids
D004277:DNA, Single-Stranded; D004279:DNA, Viral