title: Human T-cell lymphotropic virus type 1 nucleocapsid protein-induced structural changes in transactivation response DNA hairpin measured by single-molecule fluorescence resonance energy transfer.
abstract: Time-resolved single-molecule fluorescence spectroscopy was used to study the human T-cell lymphotropic virus type 1 (HTLV-1) nucleocapsid protein (NC) chaperone activity compared to that of the human immunodeficiency virus type 1 (HIV-1) NC protein. HTLV-1 NC contains two zinc fingers, each having a CCHC binding motif similar to HIV-1 NC. HIV-1 NC is required for recognition and packaging of the viral RNA and is also a nucleic acid chaperone protein that facilitates nucleic acid restructuring during reverse transcription. Because of similarities in structures between the two retroviruses, we have used single-molecule fluorescence energy transfer to investigate the chaperoning activity of the HTLV-1 NC protein. The results indicate that the HTLV-1 NC protein induces structural changes by opening the transactivation response (TAR) DNA hairpin to an even greater extent than HIV-1 NC. However, unlike HIV-1 NC, HTLV-1 NC does not chaperone the strand-transfer reaction involving TAR DNA. These results suggest that, despite its effective destabilization capability, HTLV-1 NC is not as effective at overall chaperone function as is its HIV-1 counterpart.
authors.affiliation: Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA.
authors.forename: Qusai
authors.initials: Q
authors.lastname: Darugar
authors.forename: Hannah
authors.initials: H
authors.lastname: Kim
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Gorelick
authors.forename: Christy
authors.initials: C
authors.lastname: Landes
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004279:DNA, Viral / Q000737:chemistry* / Q000235:genetics; D031541:Fluorescence Resonance Energy Transfer; D015368:Human T-lymphotropic virus 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D019590:Nucleocapsid Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics*
chemical_list: D004279:DNA, Viral; D019590:Nucleocapsid Proteins