title: A structural model for the full-length blue light-sensing protein YtvA from Bacillus subtilis, based on EPR spectroscopy.
abstract: A model for the full-length structure of the blue light-sensing protein YtvA from Bacillus subtilis has been determined by EPR spectroscopy, performed on spin labels selectively inserted at amino acid positions 54, 80, 117 and 179. Our data indicate that YtvA forms a dimer in solution and enable us, based on the known structures of the individual domains and modelling, to propose a three-dimensional model for the full length protein. Most importantly, this includes the YtvA N-terminus that has so far not been identified in any structural model. We show that our data are in agreement with the crystal structure of an engineered LOV-domain protein, YF1, that shows the N-terminus of the protein to be helical and to fold back in between the β-sheets of the two LOV domains, and argue for an identical arrangement in YtvA. While we could not detect any structural changes upon blue-light activation of the protein, this structural model now forms an ideal basis for identifying residues as targets for further spin labelling studies to detect potential conformational changes upon irradiation of the protein.
authors.affiliation: Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany. robert.bittl@fu-berlin.de.
authors.forename: Christopher
authors.initials: C
authors.lastname: Engelhard
authors.forename: Sarah
authors.initials: S
authors.lastname: Raffelberg
authors.forename: Yifen
authors.initials: Y
authors.lastname: Tang
authors.forename: Ralph P
authors.initials: RP
authors.lastname: Diensthuber
authors.forename: Andreas
authors.initials: A
authors.lastname: Möglich
authors.forename: Aba
authors.initials: A
authors.lastname: Losi
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Gärtner
authors.forename: Robert
authors.initials: R
authors.lastname: Bittl
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D008027:Light; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D013113:Spin Labels
chemical_list: D001426:Bacterial Proteins; D013113:Spin Labels