title: Functional analysis of the ComK protein of Bacillus coagulans.
abstract: The genes for DNA uptake and recombination in Bacilli are commonly regulated by the transcriptional factor ComK. We have identified a ComK homologue in Bacillus coagulans, an industrial relevant organism that is recalcitrant for transformation. Introduction of B. coagulans comK gene under its own promoter region into Bacillus subtilis comK strain results in low transcriptional induction of the late competence gene comGA, but lacking bistable expression. The promoter regions of B. coagulans comK and the comGA genes are recognized in B. subtilis and expression from these promoters is activated by B. subtilis ComK. Purified ComK protein of B. coagulans showed DNA-binding ability in gel retardation assays with B. subtilis- and B. coagulans-derived probes. These experiments suggest that the function of B. coagulans ComK is similar to that of ComK of B. subtilis. When its own comK is overexpressed in B. coagulans the comGA gene expression increases 40-fold, while the expression of another late competence gene, comC is not elevated and no reproducible DNA-uptake could be observed under these conditions. Our results demonstrate that B. coagulans ComK can recognize several B.subtilis comK-responsive elements, and vice versa, but indicate that the activation of the transcription of complete sets of genes coding for a putative DNA uptake apparatus in B. coagulans might differ from that of B. subtilis.
authors.affiliation: Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
authors.forename: Ákos T
authors.initials: ÁT
authors.lastname: Kovács
authors.forename: Tom H
authors.initials: TH
authors.lastname: Eckhardt
authors.forename: Mariska
authors.initials: M
authors.lastname: van Hartskamp
authors.forename: Richard
authors.initials: R
authors.lastname: van Kranenburg
authors.forename: Oscar P
authors.initials: OP
authors.lastname: Kuipers
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005818:Genetic Engineering / Q000379:methods; D016680:Genome, Bacterial; D023281:Genomics; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000235:genetics; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D020218:Response Elements; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D009711:Nucleotides; D014157:Transcription Factors; C087449:comK protein, Bacillus subtilis