title: The N(0)-binding region of the vesicular stomatitis virus phosphoprotein is globally disordered but contains transient α-helices.
abstract: The phosphoprotein (P) of vesicular stomatitis virus (VSV) interacts with nascent nucleoprotein (N), forming the N(0)-P complex that is indispensable for the correct encapsidation of newly synthesized viral RNA genome. In this complex, the N-terminal region (P(NTR)) of P prevents N from binding to cellular RNA and keeps it available for encapsidating viral RNA genomes. Here, using nuclear magnetic resonance (NMR) spectroscopy and small-angle X-ray scattering (SAXS), we show that an isolated peptide corresponding to the 60 first N-terminal residues of VSV P (P(60)) and encompassing P(NTR) has overall molecular dimensions and a dynamic behavior characteristic of a disordered protein but transiently populates conformers containing α-helices. The modeling of P(60) as a conformational ensemble by the ensemble optimization method using SAXS data correctly reproduces the α-helical content detected by NMR spectroscopy and suggests the coexistence of subensembles of different compactness. The populations and overall dimensions of these subensembles are affected by the addition of stabilizing (1M trimethylamine-N-oxide) or destabilizing (6M guanidinium chloride) cosolvents. Our results are interpreted in the context of a scenario whereby VSV P(NTR) constitutes a molecular recognition element undergoing a disorder-to-order transition upon binding to its partner when forming the N(0)-P complex.
authors.affiliation: Unit of Virus Host Cell Interactions, UMI 3265 UJF-EMBL-CNRS, 38042 Grenoble Cedex 9, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: Leyrat
authors.forename: Malene Ringkjøbing
authors.initials: MR
authors.lastname: Jensen
authors.forename: Euripedes A
authors.initials: EA
authors.lastname: Ribeiro
authors.forename: Francine C A
authors.initials: FC
authors.lastname: Gérard
authors.forename: Rob W H
authors.initials: RW
authors.lastname: Ruigrok
authors.forename: Martin
authors.initials: M
authors.lastname: Blackledge
authors.forename: Marc
authors.initials: M
authors.lastname: Jamin
mesh_terms: D001665:Binding Sites; D002213:Capsid / Q000737:chemistry; D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics; D046912:Multiprotein Complexes / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular; D009698:Nucleoproteins / Q000737:chemistry / Q000235:genetics; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics; D011485:Protein Binding; D017433:Protein Structure, Secondary; D053838:Scattering, Small Angle; D018116:Vesiculovirus / Q000737:chemistry*
chemical_list: D036022:Capsid Proteins; D046912:Multiprotein Complexes; D009698:Nucleoproteins; D010750:Phosphoproteins