1. Physics of Living Systems
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Ligand sensing enhances bacterial flagellar motor output via stator recruitment

  1. Farha Naaz
  2. Megha Agrawal
  3. Soumyadeep Chakraborty
  4. Mahesh S Tirumkudulu  Is a corresponding author
  5. KV Venkatesh  Is a corresponding author
  1. Indian Institute of Technology Bombay, India
Research Article
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Cite this article as: eLife 2021;10:e62848 doi: 10.7554/eLife.62848

Abstract

It is well known that flagellated bacteria, such as Escherichia coli, sense chemicals in their environment by a chemoreceptor and relay signals via a well-characterised signalling pathway to the flagellar motor. It is widely accepted that the signals change the rotation bias of the motor without influencing the motor speed. Here, we present results to the contrary and show that the bacteria is also capable of modulating motor speed on merely sensing a ligand. Step changes in concentration of non-metabolisable ligand cause temporary recruitment of stator units leading to a momentary increase in motor speeds. For metabolisable ligand, the combined effect of sensing and metabolism leads to higher motor speeds for longer durations. Experiments performed with mutant strains delineate the role of metabolism and sensing in the modulation of motor speed and show how speed changes along with changes in bias can significantly enhance response to changes in its environment.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for Figures 2, 3 and 4.

Article and author information

Author details

  1. Farha Naaz

    Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
    Competing interests
    The authors declare that no competing interests exist.
  2. Megha Agrawal

    Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
    Competing interests
    The authors declare that no competing interests exist.
  3. Soumyadeep Chakraborty

    Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
    Competing interests
    The authors declare that no competing interests exist.
  4. Mahesh S Tirumkudulu

    Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
    For correspondence
    mahesh@che.iitb.ac.in
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7046-8069
  5. KV Venkatesh

    Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
    For correspondence
    venks@iitb.ac.in
    Competing interests
    The authors declare that no competing interests exist.

Funding

Department of Biotechnology, Ministry of Science and Technology, India (BT/PR7712/BRB/10/1229/2013)

  • Mahesh S Tirumkudulu

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

Reviewing Editor

  1. Raymond E Goldstein, University of Cambridge, United Kingdom

Publication history

  1. Received: September 6, 2020
  2. Accepted: April 3, 2021
  3. Accepted Manuscript published: April 6, 2021 (version 1)

Copyright

© 2021, Naaz 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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