DNA repair in Haemophilus influenzae: isolation and characterization of an ultraviolet sensitive mutator mutant
DNA repair in Haemophilus influenzae appears to be quite different from that seen in Escherichia coli in that H. influenzae shows neither SOS nor adaptation phenomena. Repair of DNA lesions in H. influenzae has been seen to occur via recombinational, excision, and mismatch repair pathways acting independently of one another. The author has isolated an ultraviolet (UV)-sensitive mutator mutant (mutB1) of H. influenzae Rd which shows deficiencies in both recombinational and mismatch repair pathways. This mutant is sensitive to a variety of DNA damaging agents as well as being hypermutable by alkylating agents and base analogues. MutB1 cells do not show post-UV DNA breakdown but do begin excision after UV irradiation. Genetic transformation with UV-irradiated DNA on mut B1 recipients shows that high (HE) and low (LE) efficiency markers are transformed at a ratio of 1.0 as in the mismatch repair deficient hex 1 mutant; however, kinetics of UV-inactivation experiments indicate that HE markers are sensitized and act as LE markers do on wild type recipients. Thus, the mutB gene product appears to play a role in both DNA repair and genetic transformation. A model is outlined which presents a role for a DNA helicase in both DNA repair and genetic transformation of H. influenzae.
- Research Organization:
- Florida State Univ., Tallahassee (USA)
- OSTI ID:
- 5528768
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HAEMOPHILUS
DNA REPAIR
GENETIC RADIATION EFFECTS
RADIATION INDUCED MUTANTS
RADIOSENSITIVITY
BIOLOGICAL PATHWAYS
DNA HELICASES
MATHEMATICAL MODELS
ULTRAVIOLET RADIATION
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
ELECTROMAGNETIC RADIATION
ENZYMES
GENETIC EFFECTS
MICROORGANISMS
MUTANTS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
560131* - Radiation Effects on Microorganisms- Basic Studies- (-1987)