Evidence for two recA genes mediating DNA repair in Bacillus megaterium.
Isolation and subsequent knockout of a recA-homologous gene in Bacillus megaterium DSM 319 resulted in a mutant displaying increased sensitivity to mitomycin C. However, this mutant did not exhibit UV hypersensitivity, a finding which eventually led to identification of a second functional recA gene. Evidence for recA duplicates was also obtained for two other B. megaterium strains. In agreement with potential DinR boxes located within their promoter regions, expression of both genes (recA1 and recA2) was found to be damage-inducible. Transcription from the recA2 promoter was significantly higher than that of recA1. Since a recA2 knockout could not be achieved, functional complementation studies were performed in Escherichia coli. Heterologous expression in a RecA null mutant resulted in increased survival after UV irradiation and mitomycin C treatment, proving both recA gene products to be functional in DNA repair. Thus, there is evidence for an SOS-like pathway in B. megaterium that differs from that of Bacillus subtilis.
Nahrstedt
Hannes
H
Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstraße 3, 48149 Münster, Germany.
Schröder
Christine
C
Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstraße 3, 48149 Münster, Germany.
Meinhardt
Friedhelm
F
Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstraße 3, 48149 Münster, Germany.
D001410:Bacillus megaterium / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D004249:DNA Damage; D004260:DNA Repair; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D011938:Rec A Recombinases / Q000096:biosynthesis / Q000235:genetics*; D013014:SOS Response, Genetics; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D011938:Rec A Recombinases