Scripps VIVO scripps research logo

  • Index
  • Log in
  • Home
  • People
  • Organizations
  • Research
  • Events
Search form
As of April 1st VIVO Scientific Profiles will no longer updated for faculty, and the link to VIVO will be removed from the library website. Faculty profile pages will continue to be updated via Interfolio. VIVO will continue being used behind the scenes to update graduate student profiles. Please contact helplib@scripps.edu if you have questions.
How to download citations from VIVO | Alternative profile options

Effect of Mg(2+) and Na(+) on the nucleic acid chaperone activity of HIV-1 nucleocapsid protein: implications for reverse transcription

Academic Article
uri icon
  • Overview
  • Research
  • Identity
  • Additional Document Info
  • View All
scroll to property group menus

Overview

authors

  • Vo, My-Nuong
  • Barany, G.
  • Rouzina, I.
  • Musier-Forsyth, K.

publication date

  • February 2009

journal

  • Journal of Molecular Biology  Journal

abstract

  • The human immunodeficiency virus type 1 (HIV-1) nucleocapsid protein (NC) is an essential protein for retroviral replication. Among its numerous functions, NC is a nucleic acid (NA) chaperone protein that catalyzes NA rearrangements leading to the formation of thermodynamically more stable conformations. In vitro, NC chaperone activity is typically assayed under conditions of low or no Mg(2+), even though reverse transcription requires the presence of divalent cations. Here, the chaperone activity of HIV-1 NC was studied as a function of varying Na(+) and Mg(2+) concentrations by investigating the annealing of complementary DNA and RNA hairpins derived from the trans-activation response domain of the HIV genome. This reaction mimics the annealing step of the minus-strand transfer process in reverse transcription. Gel-shift annealing and sedimentation assays were used to monitor the annealing kinetics and aggregation activity of NC, respectively. In the absence of protein, a limited ability of Na(+) and Mg(2+) cations to facilitate hairpin annealing was observed, whereas NC stimulated the annealing 10(3)- to 10(5)-fold. The major effect of either NC or the cations is on the rate of bimolecular association of the hairpins. This effect is especially strong under conditions wherein NC induces NA aggregation. Titration with NC and NC/Mg(2+) competition studies showed that the annealing kinetics depends only on the level of NA saturation with NC. NC competes with Mg(2+) or Na(+) for sequence-nonspecific NA binding similar to a simple trivalent cation. Upon saturation, NC induces attraction between NA molecules corresponding to approximately 0.3 kcal/mol/nucleotide, in agreement with an electrostatic mechanism of NC-induced NA aggregation. These data provide insights into the variable effects of NC's chaperone activity observed during in vitro studies of divalent metal-dependent reverse transcription reactions and suggest the feasibility of NC-facilitated proviral DNA synthesis within the mature capsid core.

subject areas

  • Base Sequence
  • DNA, Viral
  • Electrophoretic Mobility Shift Assay
  • Enzyme Inhibitors
  • HIV-1
  • Humans
  • Kinetics
  • Magnesium
  • Models, Molecular
  • Molecular Chaperones
  • Molecular Sequence Data
  • Nucleic Acid Conformation
  • Protein Binding
  • RNA, Viral
  • Reverse Transcription
  • Sodium
  • gag Gene Products, Human Immunodeficiency Virus
scroll to property group menus

Research

keywords

  • HIV-1 nucleocapsid protein
  • electrostatics of nucleic acids
  • multivalent cations
  • nucleic acid aggregation
  • nucleic acid chaperone activity
scroll to property group menus

Identity

PubMed Central ID

  • PMC2642912

International Standard Serial Number (ISSN)

  • 0022-2836

Digital Object Identifier (DOI)

  • 10.1016/j.jmb.2008.12.073

PubMed ID

  • 19154740
scroll to property group menus

Additional Document Info

start page

  • 773

end page

  • 788

volume

  • 386

issue

  • 3

©2022 The Scripps Research Institute | Terms of Use | Powered by VIVO

  • About
  • Contact Us
  • Support