title: Prevalence of intrinsic disorder in the hepatitis C virus ARFP/Core+1/S protein.
abstract: The hepatitis C virus (HCV) Core+1/S polypeptide, also known as alternative reading frame protein (ARFP)/S, is an ARFP expressed from the Core coding region of the viral genome. Core+1/S is expressed as a result of internal initiation at AUG codons (85-87) located downstream of the polyprotein initiator codon, and corresponds to the C-terminal part of most ARFPs. Core+1/S is a highly basic polypeptide, and its function still remains unclear. In this work, untagged recombinant Core+1/S was expressed and purified from Escherichia coli in native conditions, and was shown to react with sera of HCV-positive patients. We subsequently undertook the biochemical and biophysical characterization of Core+1/S. The conformation and oligomeric state of Core+1/S were investigated using size exclusion chromatography, dynamic light scattering, fluorescence, CD, and NMR. Consistent with sequence-based disorder predictions, Core+1/S lacks significant secondary structure in vitro, which might be relevant for the recognition of diverse molecular partners and/or for the assembly of Core+1/S. This study is the first reported structural characterization of an HCV ARFP/Core+1 protein, and provides evidence that ARFP/Core+1/S is highly disordered under native conditions, with a tendency for self-association.
authors.affiliation: Université de Strasbourg, CNRS FRE 3211, Ecole Supérieure de Biotechnologie de Strasbourg, Illkirch, France.
authors.forename: Anissa
authors.initials: A
authors.lastname: Boumlic
authors.forename: Yves
authors.initials: Y
authors.lastname: Nominé
authors.forename: Sebastian
authors.initials: S
authors.lastname: Charbonnier
authors.forename: Georgia
authors.initials: G
authors.lastname: Dalagiorgou
authors.forename: Niki
authors.initials: N
authors.lastname: Vassilaki
authors.forename: Bruno
authors.initials: B
authors.lastname: Kieffer
authors.forename: Gilles
authors.initials: G
authors.lastname: Travé
authors.forename: Penelope
authors.initials: P
authors.lastname: Mavromara
authors.forename: Georges
authors.initials: G
authors.lastname: Orfanoudakis
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D003001:Cloning, Molecular; D016174:Hepacivirus / Q000235:genetics*; D006526:Hepatitis C / Q000276:immunology; D006358:Hot Temperature; D006801:Humans; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D020815:Polyproteins / Q000235:genetics; D011489:Protein Denaturation; D016415:Sequence Alignment; D013050:Spectrometry, Fluorescence; D014758:Viral Core Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology
chemical_list: D020815:Polyproteins; D014758:Viral Core Proteins; C433031:hepatitis C protein F, Hepatitis C virus