title: Secretion of Serratia liquefaciens phospholipase from Escherichia coli.
abstract: The Serratia liquefaciens phospholipase (PhlA) is secreted to the medium from its natural host. Here we present results which indicate that, when cloned and expressed in Escherichia coli, secretion can be mediated by a putative host-encoded pathway, expression of which is controlled by FlhD (formerly FlbB), the master regulator of the flagellar/chemotaxis regulon. In the absence of this secretion pathway, the synthesized phospholipase accumulates inside the host cell where it forms a complex with the PhlB protein. PhlB, which is encoded from the promoter distal gene of the phospholipase operon, inhibits the phospholipase activity of PhlA. Formation of this enzymatically inactive PhlA/PhlB complex is required for maintenance of cell viability.
authors.affiliation: Department of Microbiology, Technical University of Denmark, Lyngby.
authors.forename: M
authors.initials: M
authors.lastname: Givskov
authors.forename: S
authors.initials: S
authors.lastname: Molin
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001692:Biological Transport; D016384:Consensus Sequence; D004926:Escherichia coli / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009876:Operon; D010741:Phospholipases A / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D012705:Serratia / Q000201:enzymology* / Q000235:genetics; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D010741:Phospholipases A