title: Kinetic analysis of the nucleic acid chaperone activity of the hepatitis C virus core protein.
abstract: The multifunctional HCV core protein consists of a hydrophilic RNA interacting D1 domain and a hydrophobic D2 domain interacting with membranes and lipid droplets. The core D1 domain was found to possess nucleic acid annealing and strand transfer properties. To further understand these chaperone properties, we investigated how the D1 domain and two peptides encompassing the D1 basic clusters chaperoned the annealing of complementary canonical nucleic acids that correspond to the DNA sequences of the HIV-1 transactivation response element TAR and its complementary cTAR. The core peptides were found to augment cTAR-dTAR annealing kinetics by at least three orders of magnitude. The annealing rate was not affected by modifications of the dTAR loop but was strongly reduced by stabilization of the cTAR stem ends, suggesting that the core-directed annealing reaction is initiated through the terminal bases of cTAR and dTAR. Two kinetic pathways were identified with a fast pre-equilibrium intermediate that then slowly converts into the final extended duplex. The fast and slow pathways differed by the number of base pairs, which should be melted to nucleate the intermediates. The three peptides operate similarly, confirming that the core chaperone properties are mostly supported by its basic clusters.
authors.affiliation: Laboratorie de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401, Illkirch, Cedex, France.
authors.forename: Kamal kant
authors.initials: Kk
authors.lastname: Sharma
authors.forename: Pascal
authors.initials: P
authors.lastname: Didier
authors.forename: Jean Luc
authors.initials: JL
authors.lastname: Darlix
authors.forename: Hugues
authors.initials: H
authors.lastname: de Rocquigny
authors.forename: Hayet
authors.initials: H
authors.lastname: Bensikaddour
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Lavergne
authors.forename: François
authors.initials: F
authors.lastname: Pénin
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Lessinger
authors.forename: Yves
authors.initials: Y
authors.lastname: Mély
mesh_terms: D001483:Base Sequence; D004279:DNA, Viral / Q000737:chemistry* / Q000378:metabolism; D016325:HIV Long Terminal Repeat; D007700:Kinetics; D018832:Molecular Chaperones / Q000737:chemistry* / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry; D010455:Peptides / Q000378:metabolism; D017434:Protein Structure, Tertiary; D013050:Spectrometry, Fluorescence; D014758:Viral Core Proteins / Q000737:chemistry* / Q000378:metabolism*; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000378:metabolism
chemical_list: D004279:DNA, Viral; D018832:Molecular Chaperones; C071884:NCP7 protein, Human immunodeficiency virus 1; D009841:Oligonucleotides; D010455:Peptides; D014758:Viral Core Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C069130:nucleocapsid protein, Hepatitis C virus