Repair of nonreplicating UV-irradiated DNA: cooperative dark repair by Escherichia coli uvr and phr functions

Journal Article · Fri Feb 01 04:00:00 EST 1985 · J. Bacteriol.; (United States)

OSTI ID:5749555

Hays, J B; Martin, S J; Bhatia, K

The system previously used to study recombination of nonreplicating UV-irradiated phage lambda DNA was adapted to study UV repair. Irradiated phages infected undamaged homoimmune lysogens. Pyrimidine dimer content (by treatment with Micrococcus luteus UV endonuclease and alkaline sucrose sedimentation) and a biological activity endpoint (infectivity in transfection of uvrB recA recB spheroplasts) were followed. Unless room light was excluded during DNA extraction procedures, photoreactivation (Phr function) was significant. In uvr ..delta..phr bacteria, repair, by both assays, was very low but not zero. Even when light was totally excluded, Phr function appeared to play a role in Uvr-mediated excision repair: both dimer removal and restoration of infectivity were two to five times as efficient in uvr/sup +/ phr/sup +/ bacteria as in uvr/sup +/ ..delta..phr bacteria. Similarly, UV-irradiated phages plated with higher efficiencies on phr/sup +/ than ..delta..phr bacteria even under totally dark conditions. In uvr phr/sup +/ repressed infections, removal of dimers from nonreplicating DNA did not increase infectivity as much as in uvr2= infections, suggesting a requirement for repair of nondimer photoproducts by the uvrABC system.

• Research Organization: Univ. of Maryland Baltimore County, Catonsville
• OSTI ID: 5749555
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 161:2; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

560131* -- Radiation Effects on Microorganisms-- Basic Studies-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BACTERIOPHAGES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
DNA REPAIR
DNA-ASE
ELECTROMAGNETIC RADIATION
ENDONUCLEASES
ENZYMES
ESCHERICHIA COLI
ESTERASES
GENE RECOMBINATION
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
HYDROLASES
INFECTIVITY
MICROCOCCUS
MICROCOCCUS LUTEUS
MICROORGANISMS
PARASITES
PHOSPHODIESTERASES
PHOTOREACTIVATION
PYRIMIDINE DIMERS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
ULTRAVIOLET RADIATION
VIRUSES
VISIBLE RADIATION