The Bacillus subtilis clpC operon encodes DNA repair and competence proteins.
ClpC of Bacillus subtilis, controlling competence gene expression and survival under stress conditions, is encoded by the fourth gene of a six-gene operon. The product of orf1 contains a potential helix-turn-helix motif, but shows no significant similarities with known protein sequences. The second and third genes encode proteins with similarities to zinc-finger proteins (orf2) and arginine kinases (orf3), respectively. The product of orf5 contains a zinc-finger motif and an ATP-binding domain, and is highly similar to the product of the Escherichia coli sms gene. A strain bearing a disruption of orf5 showed increased sensitivity to the alkylating agent methyl methanesulfonate. Furthermore, this mutant strain displayed decreased capacity for genetic recombination as measured by transformation experiments. The last open reading frame, orf6, encodes a protein with limited similarity in its C-terminal part to the B. subtilis comEA gene product and to the UvrC DNA repair excinuclease. Inactivation of orf5 resulted in strongly diminished transformation with all types of DNA. Mutations affecting either orf5 or orf6 resulted in strains with decreased resistance to UV-irradiation in the stationary phase, indicating that these proteins play a role in the development of a non-specific stationary-phase resistance to UV-irradiation. Moreover, these results suggest an involvement of both proteins in transformation and presumably in DNA repair.
Krüger
EIke
E
Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität, D-17487 Greifswald, Germany.
Msadek
Tarek
T
Unité de Biochimie Microbienne, Unité de Recherche Associeé 1300 du Centre National de la Recherche Scientifique, Institut Pasteur, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France.
Ohlmeier
Steffen
S
Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität, D-17487 Greifswald, Germany.
Hecker
Michael
M
Institut für Mikrobiologie und Molekularbiologie, Ernst-Moritz-Arndt-Universität, D-17487 Greifswald, Germany.
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics* / Q000528:radiation effects; D001426:Bacterial Proteins / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D006360:Heat-Shock Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009876:Operon; D010641:Phenotype; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014170:Transformation, Genetic / Q000235:genetics*; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; C087481:ClpC protein, Bacteria; D006360:Heat-Shock Proteins