Regulated expression of the dinR and recA genes during competence development and SOS induction in Bacillus subtilis.
It has been hypothesized that the dinR gene product of Bacillus subtilis acts as a repressor of the SOS regulon by binding to DNA sequences located upstream of SOS genes, including dinR and recA. Following activation as a result of DNA damage, RecA is believed to catalyse DinR-autocleavage, thus derepressing the SOS regulon. The present results support this hypothesis: a dinR insertion mutation caused a high, constitutive expression of both dinR and recA, which could not be further elevated by SOS-induction. In addition, gel-retardation assays demonstrated a direct interaction between the dinR gene product and the recA and dinR promoter regions. Epistatic interactions and gel-retardation assays demonstrated that the previously reported competence-specific expression of recA directly depended upon the gene product of comK, the competence transcription factor. These data demonstrate the existence of a direct regulatory link between the competence signal-transduction pathway and the SOS reguion.
Department of Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands.
B J
BJ
Haijema
D
D
van Sinderen
K
K
Winterling
J
J
Kooistra
G
G
Venema
L W
LW
Hamoen
D001412:Bacillus subtilis / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015139:Blotting, Southern; D015153:Blotting, Western; D018983:DNA Footprinting; D004843:Epistasis, Genetic; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins; D013014:SOS Response, Genetics / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C071577:dinR protein, Bacillus subtilis; C087449:comK protein, Bacillus subtilis; D011938:Rec A Recombinases