title: HIV-1 nucleocapsid protein bends double-stranded nucleic acids.
abstract: The human immunodeficiency virus type-1 (HIV-1) nucleocapsid (NC) protein is believed to be unique among the nucleic acid (NA) binding proteins encoded by this retrovirus in being highly multifunctional and relatively nonsequence-specific. Underlying many of NC's putative functions, including for example its chaperon-like activity for various steps of HIV-1 reverse transcription, is NC's ability to partially melt short double-stranded regions of structured NAs, which is essentially a consequence of NC's general binding preference for single-stranded bases. Herein we report a different, previously undiscovered, mode of NC/NA interaction, i.e., NC-induced sharp bending of short segments of fully duplexed DNA/DNA and DNA/RNA. We use single-molecule fluorescence resonance energy transfer (SM-FRET) in vitro to probe NC-induced NA bending and associated heterogeneous conformational dynamics for model NC/NA complexes. NC-induced NA bending may have important biological roles in the previously reported NC-mediated condensation of duplex proviral DNA in the HIV-1 life cycle.
authors.affiliation: Center for Nano and Molecular Science and Technology and Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Yu-Shan
authors.initials: YS
authors.lastname: Yeh
authors.forename: Paul F
authors.initials: PF
authors.lastname: Barbara
mesh_terms: D000595:Amino Acid Sequence; D004247:DNA / Q000737:chemistry*; D015497:HIV-1 / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D019590:Nucleocapsid Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: D019590:Nucleocapsid Proteins; D004247:DNA