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[Phenomenon of w-reactivation in plasmids]
Molekuliarnaia Biologiia
|January 1, 1978
Abstract:
An analysis of the action of the bacterial repair system on the UV-irradiated pMB9 plasmid has been carried out. It has been shown that the UV-irradiated plasmid is repaired in the bacteria similarly to the DNA of bacteriophage (lambda): the effectiveness of the UVR-system is lowered two-three times, and the postreplicativing REC system acts only at low doses of the UV-light. The phenomenon of omega-reactivation is observed both with plasmid and phage DNAs.
Insights
Bacterial repair systems act on UV-damaged pMB9 plasmid DNA similarly to bacteriophage DNA. The UVR-system
Area of Science:
- Molecular Biology
- Microbiology
- Genetics
Background:
- Ultraviolet (UV) radiation induces DNA damage in plasmids and bacteriophages.
- Bacterial DNA repair mechanisms are crucial for maintaining genomic integrity.
- Understanding plasmid DNA repair provides insights into broader DNA repair pathways.
Purpose of the Study:
- To analyze the action of bacterial repair systems on UV-irradiated pMB9 plasmid DNA.
- To compare the repair efficiency of plasmid DNA with bacteriophage DNA.
- To investigate the dose-dependent activity of specific repair systems.
Main Methods:
- Exposure of pMB9 plasmid to UV irradiation.
- Incubation of UV-irradiated plasmid in bacterial hosts.
- Analysis of plasmid survival and repair.
- Comparison with bacteriophage DNA repair data.
Main Results:
- UV-irradiated plasmid DNA is repaired by bacterial systems.
- The UVR-system's effectiveness is reduced (2-3 fold) on plasmid DNA compared to phage DNA.
- The post-replicative REC system shows activity only at low UV doses for plasmid DNA.
- Omega-reactivation is observed for both plasmid and phage DNA.
Conclusions:
- Bacterial repair systems exhibit similar action on UV-damaged plasmid and bacteriophage DNA.
- The UVR and REC systems have specific efficiencies and dose-dependencies when acting on plasmid DNA.
- Omega-reactivation is a conserved phenomenon across different DNA types in bacteria.