Initiation of transcription-coupled repair characterized at single-molecule resolution Academic Article uri icon

Overview

MeSH Major

  • Bacterial Proteins
  • DNA Repair
  • Transcription Factors
  • Transcription, Genetic

abstract

  • Transcription-coupled DNA repair uses components of the transcription machinery to identify DNA lesions and initiate their repair. These repair pathways are complex, so their mechanistic features remain poorly understood. Bacterial transcription-coupled repair is initiated when RNA polymerase stalled at a DNA lesion is removed by Mfd, an ATP-dependent DNA translocase. Here we use single-molecule DNA nanomanipulation to observe the dynamic interactions of Escherichia coli Mfd with RNA polymerase elongation complexes stalled by a cyclopyrimidine dimer or by nucleotide starvation. We show that Mfd acts by catalysing two irreversible, ATP-dependent transitions with different structural, kinetic and mechanistic features. Mfd remains bound to the DNA in a long-lived complex that could act as a marker for sites of DNA damage, directing assembly of subsequent DNA repair factors. These results provide a framework for considering the kinetics of transcription-coupled repair in vivo, and open the way to reconstruction of complete DNA repair pathways at single-molecule resolution.

publication date

  • October 18, 2012

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC3475728

Digital Object Identifier (DOI)

  • 10.1038/nature11430

PubMed ID

  • 22960746

Additional Document Info

start page

  • 431

end page

  • 4

volume

  • 490

number

  • 7420