title: The heat shock genes dnaK, dnaJ, and grpE are involved in regulation of putisolvin biosynthesis in Pseudomonas putida PCL1445.
abstract: Pseudomonas putida PCL1445 produces two cyclic lipopeptides, putisolvins I and II, which possess surfactant activity and play an important role in biofilm formation and degradation. In order to identify genes and traits that are involved in the regulation of putisolvin production of PCL1445, a Tn5luxAB library was generated and mutants were selected for the lack of biosurfactant production using a drop-collapsing assay. Sequence analysis of the Tn5luxAB flanking region of one biosurfactant mutant, strain PCL1627, showed that the transposon had inserted in a dnaK homologue which is located downstream of grpE and upstream of dnaJ. Analysis of putisolvin production and expression studies indicate that dnaK, together with the dnaJ and grpE heat shock genes, takes part in the positive regulation (directly or indirectly) of putisolvin biosynthesis at the transcriptional level. Growth of PCL1445 at low temperature resulted in an increased level of putisolvins, and mutant analyses showed that this requires dnaK and dnaJ but not grpE. In addition, putisolvin biosynthesis of PCL1445 was found to be dependent on the GacA/GacS two-component signaling system. Expression analysis indicated that dnaK is positively regulated by GacA/GacS.
authors.affiliation: Leiden University, Institute of Biology, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands.
authors.forename: Jean-Frédéric
authors.initials: JF
authors.lastname: Dubern
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Lagendijk
authors.forename: Ben J J
authors.initials: BJ
authors.lastname: Lugtenberg
authors.forename: Guido V
authors.initials: GV
authors.lastname: Bloemberg
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002876:Chromosomes, Bacterial / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D015723:Gene Library; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000096:biosynthesis*; D015183:Restriction Mapping; D013501:Surface-Active Agents
chemical_list: D001426:Bacterial Proteins; C068113:GrpE protein, Bacteria; D006360:Heat-Shock Proteins; D010456:Peptides, Cyclic; D013501:Surface-Active Agents; C481658:putisolvin I; C481659:putisolvin II