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Regulated expression of the dinR and recA genes during competence development and SOS induction in Bacillus subtilis
Author(s) -
Haijema Bert Jan,
Sinderen Douwe,
Winterling Kevin,
Kooistra Jan,
Venema Gerard,
Hamoen Leendert Willem
Publication year - 1996
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1996.tb02657.x
Subject(s) - regulon , biology , bacillus subtilis , repressor lexa , repressor , gene , genetics , sos response , transcription factor , transcription (linguistics) , regulation of gene expression , promoter , gene expression , microbiology and biotechnology , dna repair , bacteria , linguistics , philosophy
Summary 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 regulon.