title: PspF-binding domain PspA1-144 and the PspA·F complex: New insights into the coiled-coil-dependent regulation of AAA+ proteins.
abstract: Phage shock protein A (PspA) belongs to the highy conserved PspA/IM30 family and is a key component of the stress inducible Psp system in Escherichia coli. One of its central roles is the regulatory interaction with the transcriptional activator of this system, the σ(54) enhancer-binding protein PspF, a member of the AAA+ protein family. The PspA/F regulatory system has been intensively studied and serves as a paradigm for AAA+ enzyme regulation by trans-acting factors. However, the molecular mechanism of how exactly PspA controls the activity of PspF and hence σ(54) -dependent expression of the psp genes is still unclear. To approach this question, we identified the minimal PspF-interacting domain of PspA, solved its structure, determined its affinity to PspF and the dissociation kinetics, identified residues that are potentially important for PspF regulation and analyzed effects of their mutation on PspF in vivo and in vitro. Our data indicate that several characteristics of AAA+ regulation in the PspA·F complex resemble those of the AAA+ unfoldase ClpB, with both proteins being regulated by a structurally highly conserved coiled-coil domain. The convergent evolution of both regulatory domains points to a general mechanism to control AAA+ activity for divergent physiologic tasks via coiled-coil domains.
authors.affiliation: Institute of Microbiology, Leibniz Universität Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Osadnik
authors.affiliation: Institute of Biochemistry and Biotechnology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle (Saale), 06120, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schöpfel
authors.affiliation: Institute of Microbiology, Leibniz Universität Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany.
authors.forename: Eyleen
authors.initials: E
authors.lastname: Heidrich
authors.affiliation: Institute of Microbiology, Leibniz Universität Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany.
authors.forename: Denise
authors.initials: D
authors.lastname: Mehner
authors.affiliation: Institute of Biochemistry and Biotechnology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle (Saale), 06120, Germany.
authors.forename: Hauke
authors.initials: H
authors.lastname: Lilie
authors.affiliation: Institute of Biochemistry and Biotechnology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle (Saale), 06120, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Parthier
authors.affiliation: Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, 37077, Germany.
authors.forename: H Jelger
authors.initials: HJ
authors.lastname: Risselada
authors.affiliation: Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, 37077, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Grubmüller
authors.affiliation: Institute of Biochemistry and Biotechnology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle (Saale), 06120, Germany.
authors.forename: Milton T
authors.initials: MT
authors.lastname: Stubbs
authors.affiliation: Institute of Microbiology, Leibniz Universität Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Brüser
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D049071:Endopeptidase Clp; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; C098954:PspF protein, E coli; D012808:Sigma Factor; D015534:Trans-Activators; C069816:phage shock protein, Bacteria; D049071:Endopeptidase Clp; C069775:ClpB protein, E coli