Single-molecule pull-down for investigating protein-nucleic acid interactions

Methods. 2016 Aug 1:105:99-108. doi: 10.1016/j.ymeth.2016.03.022. Epub 2016 Mar 25.

Abstract

The genome and transcriptome are constantly modified by proteins in the cell. Recent advances in single-molecule techniques allow for high spatial and temporal observations of these interactions between proteins and nucleic acids. However, due to the difficulty of obtaining functional protein complexes, it remains challenging to study the interactions between macromolecular protein complexes and nucleic acids. Here, we combined single-molecule fluorescence with various protein complex pull-down techniques to determine the function and stoichiometry of ribonucleoprotein complexes. Through the use of three examples of protein complexes from eukaryotic cells (Drosha, Dicer, and TUT4 protein complexes), we provide step-by-step guidance for using novel single-molecule techniques. Our single-molecule methods provide sub-second and nanometer resolution and can be applied to other nucleoprotein complexes that are essential for cellular processes.

Keywords: Dicer; Drosha; Protein complex; RNA interference; Single-molecule fluorescence; Single-protein pull-down; TUT4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DEAD-box RNA Helicases / chemistry
  • DEAD-box RNA Helicases / genetics
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / genetics
  • Humans
  • Microscopy, Fluorescence / methods*
  • Multiprotein Complexes / chemistry*
  • Multiprotein Complexes / genetics
  • Nanotechnology / methods
  • Nucleic Acids / chemistry
  • Nucleic Acids / genetics
  • Ribonuclease III / chemistry
  • Ribonuclease III / genetics
  • Single Molecule Imaging / methods*

Substances

  • DNA-Binding Proteins
  • Multiprotein Complexes
  • Nucleic Acids
  • DICER1 protein, human
  • Ribonuclease III
  • DEAD-box RNA Helicases