title: Genetic and functional analyses of krs, a locus encoding kurstakin, a lipopeptide produced by Bacillus thuringiensis.
abstract: Bacteria of the Bacillus genus are able to synthesize several families of lipopeptides. These small molecules are the product of non-ribosomal peptide synthetases. In 2000, it was found that Bacillus thuringiensis, an entomopathogenic bacterium of the Bacillus cereus group, produced a previously unknown lipopeptide: kurstakin. Genomic analyses reveal that the krs locus, encoding the kurstakin synthetases, is specific to the B. cereus group, but is unevenly distributed within this group. Previous work showed that krs transcription requires the necrotrophism quorum-sensor NprR. Here, we demonstrated that the genes of the krs locus form an operon and we defined its transcription start site. Following krs transcription at the population and single-cell levels in multiple culture conditions, we depicted a condition-dependent transcription pattern, indicating that production of kurstakin is subject to environmental regulation. Consistent with this idea, we found krs transcription to be regulated by another master regulator, Spo0A, suggesting that krs expression is fine-tuned by integrating multiple signals. We also reported an unknown DNA palindrome in the krs promoter region that modulates krs expression. Due to their surfactant properties, lipopeptides could play several physiological roles. We showed that the krs locus was required for proper biofilm structuration.
authors.affiliation: Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France. Electronic address: sebastien@gelis.ch.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Gélis-Jeanvoine
authors.affiliation: Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France. Electronic address: acanette@jouy.inra.fr.
authors.forename: Alexis
authors.initials: A
authors.lastname: Canette
authors.affiliation: Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France. Electronic address: michel.gohar@jouy.inra.fr.
authors.forename: Michel
authors.initials: M
authors.lastname: Gohar
authors.affiliation: University of Lille, EA 7394, ICV-Institut Charles Viollette, ProBioGEM Team, Polytech'Lille, Avenue Langevin, 59655 Villeneuve d'Ascq, France. Electronic address: caradec.thibault@hotmail.com.
authors.forename: Thibault
authors.initials: T
authors.lastname: Caradec
authors.affiliation: Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France. Electronic address: christelle.lemy@jouy.inra.fr.
authors.forename: Christelle
authors.initials: C
authors.lastname: Lemy
authors.affiliation: Institut Pasteur, CNRS URA 2172, Unité de Biologie des Bactéries Pathogènes à Gram positif, 75015 Paris, France. Electronic address: myriam.gominet@pasteur.fr.
authors.forename: Myriam
authors.initials: M
authors.lastname: Gominet
authors.affiliation: University of Lille, EA 7394, ICV-Institut Charles Viollette, ProBioGEM Team, Polytech'Lille, Avenue Langevin, 59655 Villeneuve d'Ascq, France. Electronic address: philippe.jacques@ulg.ac.be.
authors.forename: Philippe
authors.initials: P
authors.lastname: Jacques
authors.affiliation: Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France. Electronic address: leyla.slamti@jouy.inra.fr.
authors.forename: Didier
authors.initials: D
authors.lastname: Lereclus
authors.affiliation: Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France. Electronic address: Didier.Lereclus@jouy.inra.fr.
authors.forename: Leyla
authors.initials: L
authors.lastname: Slamti
mesh_terms: D001413:Bacillus thuringiensis / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D055666:Lipopeptides / Q000235:genetics* / Q000378:metabolism; D009876:Operon / Q000235:genetics; D046908:Peptide Biosynthesis, Nucleic Acid-Independent / Q000502:physiology*; D011401:Promoter Regions, Genetic; D053038:Quorum Sensing / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D055666:Lipopeptides
keywords: Bacillus cereus group; Biofilm; Spo0A; Transcriptional regulation