Functional properties of Borrelia burgdorferi recA.
Functions of the Borrelia burgdorferi RecA protein were investigated in Escherichia coli recA null mutants. Complementation with B. burgdorferi recA increased survival of E. coli recA mutants by 3 orders of magnitude at a UV dose of 2,000 microJ/cm(2). The viability at this UV dose was about 10% that provided by the homologous recA gene. Expression of B. burgdorferi recA resulted in survival of E. coli at levels of mitomycin C that were lethal to noncomplemented hosts. B. burgdorferi RecA was as effective as E. coli RecA in mediating homologous recombination in E. coli. Furthermore, E. coli lambda phage lysogens complemented with B. burgdorferi recA produced phage even in the absence of UV irradiation. The level of phage induction was 55-fold higher than the level in cells complemented with the homologous recA gene, suggesting that B. burgdorferi RecA may possess an enhanced coprotease activity. This study indicates that B. burgdorferi RecA mediates the same functions in E. coli as the homologous E. coli protein mediates. However, the rapid loss of viability and the absence of induction in recA expression after UV irradiation in B. burgdorferi suggest that recA is not involved in the repair of UV-induced damage in B. burgdorferi. The primary role of RecA in B. burgdorferi is likely to be a role in some aspect of recombination.
Liveris
Dionysios
D
Department of Microbiology & Immunology, New York Medical College, Valhalla, New York 10595, USA. dionysios_liveris@nymc.edu
Mulay
Vishwaroop
V
Schwartz
Ira
I
D010582:Bacteriophage lambda; D025065:Borrelia burgdorferi / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D005798:Genes, Bacterial / Q000502:physiology*; D008242:Lysogeny; D016685:Mitomycin / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D011938:Rec A Recombinases / Q000235:genetics*; D014774:Virulence / Q000235:genetics
D019384:Nucleic Acid Synthesis Inhibitors; D016685:Mitomycin; D011938:Rec A Recombinases