Torque, but not FliL, regulates mechanosensitive flagellar motor-function
Abstract The stator-complex in the bacterial flagellar motor is responsible for surface-sensing. It remodels in response to perturbations in viscous loads, recruiting additional stator-units as the load increases. Here, we tested a hypothesis that the amount of torque generated by each stator-unit m...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2017-07-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-017-05521-8 |
| _version_ | 1818993851836137472 |
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| author | Ravi Chawla Katie M. Ford Pushkar P. Lele |
| author_facet | Ravi Chawla Katie M. Ford Pushkar P. Lele |
| author_sort | Ravi Chawla |
| collection | DOAJ |
| description | Abstract The stator-complex in the bacterial flagellar motor is responsible for surface-sensing. It remodels in response to perturbations in viscous loads, recruiting additional stator-units as the load increases. Here, we tested a hypothesis that the amount of torque generated by each stator-unit modulates its association with the rotor. To do this, we measured stator-binding to the rotor in mutants in which motors reportedly develop lower torque compared to wildtype motors. First, we employed a strain lacking fliL. Contrary to earlier reports, measurements indicated that the torque generated by motors in the fliL strain was similar to that in the wildtype, at high loads. In these motors, stator-binding was unchanged. Next, experiments with a paralyzed strain indicated that the stator-binding was measurably weaker when motors were unable to generate torque. An analytical model was developed that incorporated an exponential dependence of the unit’s dissociation rate on the force delivered to the rotor. The model provided accurate fits to measurements of stator-rotor binding over a wide range of loads. Based on these results, we propose that the binding of each stator-unit is enhanced by the force it develops. Furthermore, FliL does not play a significant role in motor function in E. coli. |
| first_indexed | 2024-12-20T20:48:38Z |
| format | Article |
| id | doaj.art-d5b89c12869d4a4882eb491dd6fe1569 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-20T20:48:38Z |
| publishDate | 2017-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-d5b89c12869d4a4882eb491dd6fe15692022-12-21T19:26:59ZengNature PortfolioScientific Reports2045-23222017-07-01711910.1038/s41598-017-05521-8Torque, but not FliL, regulates mechanosensitive flagellar motor-functionRavi Chawla0Katie M. Ford1Pushkar P. Lele2Artie McFerrin Department of Chemical Engineering, Texas A&M UniversityArtie McFerrin Department of Chemical Engineering, Texas A&M UniversityArtie McFerrin Department of Chemical Engineering, Texas A&M UniversityAbstract The stator-complex in the bacterial flagellar motor is responsible for surface-sensing. It remodels in response to perturbations in viscous loads, recruiting additional stator-units as the load increases. Here, we tested a hypothesis that the amount of torque generated by each stator-unit modulates its association with the rotor. To do this, we measured stator-binding to the rotor in mutants in which motors reportedly develop lower torque compared to wildtype motors. First, we employed a strain lacking fliL. Contrary to earlier reports, measurements indicated that the torque generated by motors in the fliL strain was similar to that in the wildtype, at high loads. In these motors, stator-binding was unchanged. Next, experiments with a paralyzed strain indicated that the stator-binding was measurably weaker when motors were unable to generate torque. An analytical model was developed that incorporated an exponential dependence of the unit’s dissociation rate on the force delivered to the rotor. The model provided accurate fits to measurements of stator-rotor binding over a wide range of loads. Based on these results, we propose that the binding of each stator-unit is enhanced by the force it develops. Furthermore, FliL does not play a significant role in motor function in E. coli.https://doi.org/10.1038/s41598-017-05521-8 |
| spellingShingle | Ravi Chawla Katie M. Ford Pushkar P. Lele Torque, but not FliL, regulates mechanosensitive flagellar motor-function Scientific Reports |
| title | Torque, but not FliL, regulates mechanosensitive flagellar motor-function |
| title_full | Torque, but not FliL, regulates mechanosensitive flagellar motor-function |
| title_fullStr | Torque, but not FliL, regulates mechanosensitive flagellar motor-function |
| title_full_unstemmed | Torque, but not FliL, regulates mechanosensitive flagellar motor-function |
| title_short | Torque, but not FliL, regulates mechanosensitive flagellar motor-function |
| title_sort | torque but not flil regulates mechanosensitive flagellar motor function |
| url | https://doi.org/10.1038/s41598-017-05521-8 |
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