title: Signal Transduction by BvgS Sensor Kinase: BINDING OF MODULATOR NICOTINATE AFFECTS THE CONFORMATION AND DYNAMICS OF THE ENTIRE PERIPLASMIC MOIETY.
abstract: The two-component sensory transduction system BvgAS controls the virulence regulon of the whooping-cough agent Bordetella pertussis. The periplasmic moiety of the homodimeric sensor kinase BvgS is composed of four bilobed Venus flytrap (VFT) perception domains followed by α helices that extend into the cytoplasmic membrane. In the virulent phase, the default state of B. pertussis, the cytoplasmic enzymatic moiety of BvgS acts as kinase by autophosphorylating and transferring the phosphoryl group to the response regulator BvgA. Under laboratory conditions, BvgS shifts to phosphatase activity in response to modulators, notably nicotinate ions. Here we characterized the effects of nicotinate and related modulators on the BvgS periplasmic moiety by using site-directed mutagenesis and in silico and biophysical approaches. Modulators bind with low affinity to BvgS in the VFT2 cavity. Electron paramagnetic resonance shows that their binding globally affects the conformation and dynamics of the periplasmic moiety. Specific amino acid substitutions designed to slacken interactions within and between the VFT lobes prevent BvgS from responding to nicotinate, showing that BvgS shifts from kinase to phosphatase activity in response to this modulator via a tense transition state that involves a large periplasmic structural block. We propose that this transition enables the transmembrane helices to adopt a distinct conformation that sets the cytoplasmic enzymatic moiety in the phosphatase mode. The bona fide, in vivo VFT ligands that remain to be identified are likely to trigger similar effects on the transmembrane and cytoplasmic moieties. This mechanism may be relevant to the other VFT-containing sensor kinases homologous to BvgS.
authors.affiliation: From the Institut Pasteur de Lille, Center for Infection and Immunity of Lille, 59019 Lille Cedex, France, the Université Lille Nord de France, 59000 Lille, France, the CNRS, Unité mixte de recherche (UMR) 8204, 59046 Lille, France, the INSERM, U1019, 59045 Lille, France.
authors.forename: Elian
authors.initials: E
authors.lastname: Dupré
authors.affiliation: From the Institut Pasteur de Lille, Center for Infection and Immunity of Lille, 59019 Lille Cedex, France, the Université Lille Nord de France, 59000 Lille, France, the CNRS, Unité mixte de recherche (UMR) 8204, 59046 Lille, France, the INSERM, U1019, 59045 Lille, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Lesne
authors.affiliation: From the Institut Pasteur de Lille, Center for Infection and Immunity of Lille, 59019 Lille Cedex, France, the Université Lille Nord de France, 59000 Lille, France, the CNRS, Unité mixte de recherche (UMR) 8204, 59046 Lille, France, the INSERM, U1019, 59045 Lille, France.
authors.forename: Jérémy
authors.initials: J
authors.lastname: Guérin
authors.affiliation: the Université Lille Nord de France, 59000 Lille, France, the Unité de Glycobiologie Structurale et Fonctionnelle, CNRS, UMR 8576, 59658 Villeneuve d'Ascq, France, and.
authors.forename: Marc F
authors.initials: MF
authors.lastname: Lensink
authors.affiliation: the Université Lille Nord de France, 59000 Lille, France, the Unité de Glycobiologie Structurale et Fonctionnelle, CNRS, UMR 8576, 59658 Villeneuve d'Ascq, France, and.
authors.forename: Alexis
authors.initials: A
authors.lastname: Verger
authors.affiliation: the Université Lille Nord de France, 59000 Lille, France, the Unité de Glycobiologie Structurale et Fonctionnelle, CNRS, UMR 8576, 59658 Villeneuve d'Ascq, France, and.
authors.forename: Jérôme
authors.initials: J
authors.lastname: de Ruyck
authors.affiliation: the Université Lille Nord de France, 59000 Lille, France, the Unité de Glycobiologie Structurale et Fonctionnelle, CNRS, UMR 8576, 59658 Villeneuve d'Ascq, France, and.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Brysbaert
authors.affiliation: the Université Lille Nord de France, 59000 Lille, France, the Laboratoire de spectrochimie infrarouge et Raman (LASIR), CNRS, UMR 8516, 59658 Villeneuve d'Ascq, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Vezin
authors.affiliation: From the Institut Pasteur de Lille, Center for Infection and Immunity of Lille, 59019 Lille Cedex, France, the Université Lille Nord de France, 59000 Lille, France, the CNRS, Unité mixte de recherche (UMR) 8204, 59046 Lille, France, the INSERM, U1019, 59045 Lille, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Locht
authors.affiliation: From the Institut Pasteur de Lille, Center for Infection and Immunity of Lille, 59019 Lille Cedex, France, the Université Lille Nord de France, 59000 Lille, France, the CNRS, Unité mixte de recherche (UMR) 8204, 59046 Lille, France, the INSERM, U1019, 59045 Lille, France, rudy.antoine@pasteur-lille.fr.
authors.forename: Rudy
authors.initials: R
authors.lastname: Antoine
authors.affiliation: From the Institut Pasteur de Lille, Center for Infection and Immunity of Lille, 59019 Lille Cedex, France, the Université Lille Nord de France, 59000 Lille, France, the CNRS, Unité mixte de recherche (UMR) 8204, 59046 Lille, France, the INSERM, U1019, 59045 Lille, France, francoise.jacob@ibl.cnrs.fr.
authors.forename: Françoise
authors.identifier: http://orcid.org/0000-0002-5102-1704
authors.initials: F
authors.lastname: Jacob-Dubuisson
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001886:Bordetella pertussis / Q000201:enzymology* / Q000235:genetics; D002462:Cell Membrane / Q000201:enzymology* / Q000235:genetics; D009525:Niacin / Q000235:genetics / Q000378:metabolism*; D019897:Periplasm / Q000201:enzymology / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D009525:Niacin; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases
keywords: Bordetella virulence; Gram-negative bacteria; Venus flytrap domain; bacterial signal transduction; electron paramagnetic resonance (EPR); membrane protein; sensor kinase; signal transduction; two-component; virulence factor