NusG inhibits RNA polymerase backtracking by stabilizing the minimal transcription bubble

  1. Matti Turtola
  2. Georgiy A Belogurov  Is a corresponding author
  1. University of Turku, Finland

Abstract

Universally conserved factors from NusG family bind at the upstream fork junction of transcription elongation complexes and modulate RNA synthesis in response to translation, processing, and folding of the nascent RNA. Escherichia coli NusG enhances transcription elongation in vitro by a poorly understood mechanism. Here we report that E. coli NusG slows Gre factor-stimulated cleavage of the nascent RNA, but does not measurably change the rates of single nucleotide addition and translocation by a non-paused RNA polymerase. We demonstrate that NusG slows RNA cleavage by inhibiting backtracking. This activity is abolished by mismatches in the upstream DNA and is independent of the gate and rudder loops, but is partially dependent on the lid loop. Our comprehensive mapping of the upstream fork junction by base analogue fluorescence and nucleic acids crosslinking suggests that NusG inhibits backtracking by stabilizing the minimal transcription bubble.

Article and author information

Author details

  1. Matti Turtola

    Department of Biochemistry, University of Turku, Turku, Finland
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1694-1027
  2. Georgiy A Belogurov

    Department of Biochemistry, University of Turku, Turku, Finland
    For correspondence
    gebelo@utu.fi
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3070-6843

Funding

Suomen Akatemia (grant #286205)

  • Matti Turtola
  • Georgiy A Belogurov

Turun Yliopisto (Graduate Student Fellowship)

  • Matti Turtola

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Robert Landick, University of Wisconsin-madison, United States

Publication history

  1. Received: May 23, 2016
  2. Accepted: October 3, 2016
  3. Accepted Manuscript published: October 4, 2016 (version 1)
  4. Version of Record published: November 8, 2016 (version 2)

Copyright

© 2016, Turtola & Belogurov

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Matti Turtola
  2. Georgiy A Belogurov
(2016)
NusG inhibits RNA polymerase backtracking by stabilizing the minimal transcription bubble
eLife 5:e18096.
https://doi.org/10.7554/eLife.18096
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