Probing SWI/SNF remodeling of the nucleosome by unzipping single DNA molecules. Academic Article uri icon

Overview

abstract

  • Chromatin-remodeling enzymes can overcome strong histone-DNA interactions within the nucleosome to regulate access of DNA-binding factors to the genetic code. By unzipping individual DNA duplexes, each containing a uniquely positioned nucleosome flanked by long segments of DNA, we directly probed histone-DNA interactions. The resulting disruption-force signatures were characteristic of the types and locations of interactions and allowed measurement of the positions of nucleosomes with 2.6-base-pair (bp) precision. Nucleosomes remodeled by yeast SWI/SNF were moved bidirectionally along the DNA, resulting in a continuous position distribution. The characteristic distance of motion was approximately 28 bp per remodeling event, and each event occurred with a catalytic efficiency of 0.4 min(-1) per nM SWI/SNF. Remodeled nucleosomes had essentially identical disruption signatures to those of unremodeled nucleosomes, indicating that their overall structure remained canonical. These results impose substantial constraints on the mechanism of SWI/SNF remodeling.

publication date

  • May 28, 2006

Research

keywords

  • Chromosomal Proteins, Non-Histone
  • DNA
  • Nucleosomes
  • Transcription Factors

Identity

Scopus Document Identifier

  • 33744900357

PubMed ID

  • 16732285

Additional Document Info

volume

  • 13

issue

  • 6