1. Chromosomes and Gene Expression
  2. Microbiology and Infectious Disease

The primary σ factor in Escherichia coli can access the transcription elongation complex from solution in vivo

  1. Seth R Goldman
  2. Nikhil U Nair
  3. Christopher D Wells
  4. Bryce E Nickels
  5. Ann Hochschild  Is a corresponding author
  1. Harvard Medical School, United States
  2. Rutgers University, United States
https://doi.org/10.7554/eLife.10514
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  1. Seth R Goldman
  2. Nikhil U Nair
  3. Christopher D Wells
  4. Bryce E Nickels
  5. Ann Hochschild
(2015)
The primary σ factor in Escherichia coli can access the transcription elongation complex from solution in vivo
eLife 4:e10514.
https://doi.org/10.7554/eLife.10514
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Abstract

The σ subunit of bacterial RNA polymerase (RNAP) confers on the enzyme the ability to initiate promoter-specific transcription. Although σ factors are generally classified as initiation factors, σ can also remain associated with, and modulate the behavior of, RNAP during elongation. Here we establish that the primary σ factor in Escherichia coli, σ70, can function as an elongation factor in vivo by loading directly onto the transcription elongation complex (TEC) in trans. We demonstrate that σ70 can bind in trans to TECs that emanate from either a σ70-dependent promoter or from a promoter that is controlled by an alternative σ factor. We further demonstrate that binding of σ70 to the TEC in trans can have a particularly large impact on the dynamics of transcription elongation during stationary phase. Our findings establish a mechanism whereby the primary σ factor can exert direct effects on the composition of the entire transcriptome, not just that portion that is produced under the control of σ70-dependent promoters.

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Author details

  1. Seth R Goldman

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  2. Nikhil U Nair

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  3. Christopher D Wells

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    Competing interests
    The authors declare that no competing interests exist.

  4. Bryce E Nickels

    Department of Genetics, Waksman Institute, Rutgers University, New Brunswick, United States
    Competing interests
    The authors declare that no competing interests exist.

  5. Ann Hochschild

    Department of Microbiology and Immunobiology, Harvard Medical School, Boston, United States
    For correspondence
    ahochschild@hms.harvard.edu
    Competing interests
    The authors declare that no competing interests exist.

Copyright

© 2015, Goldman et al.

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. Seth R Goldman
  2. Nikhil U Nair
  3. Christopher D Wells
  4. Bryce E Nickels
  5. Ann Hochschild
(2015)
The primary σ factor in Escherichia coli can access the transcription elongation complex from solution in vivo
eLife 4:e10514.
https://doi.org/10.7554/eLife.10514

Share this article

https://doi.org/10.7554/eLife.10514

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