Mechanism and kinetics of a sodium-driven bacterial flagellar motor
The bacterial flagellar motor is a large rotary molecular machine that propels swimming bacteria, powered by a transmembrane electrochemical potential difference. It consists of an ∼50-nm rotor and up to ∼10 independent stators anchored to the cell wall. We measured torque-speed relationships of sin...
| Main Authors: | , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
National Academy of Sciences
2013
|
| _version_ | 1797073978266746880 |
|---|---|
| author | Lo, C Sowa, Y Pilizota, T Berry, R Lo, C Sowa, Y Pilizota, T Berry, R |
| author_facet | Lo, C Sowa, Y Pilizota, T Berry, R Lo, C Sowa, Y Pilizota, T Berry, R |
| author_sort | Lo, C |
| collection | OXFORD |
| description | The bacterial flagellar motor is a large rotary molecular machine that propels swimming bacteria, powered by a transmembrane electrochemical potential difference. It consists of an ∼50-nm rotor and up to ∼10 independent stators anchored to the cell wall. We measured torque-speed relationships of single-stator motors under 25 different combinations of electrical and chemical potential. All 25 torque-speed curves had the same concave-down shape as fully energized wild-type motors, and each stator passes at least 37 ± 2 ions per revolution. We used the results to explore the 25-dimensional parameter space of generalized kinetic models for the motor mechanism, finding 830 parameter sets consistent with the data. Analysis of these sets showed that the motor mechanism has a "powerstroke" in either ion binding or transit; ion transit is channel-like rather than carrier-like; and the rate-limiting step in the motor cycle is ion binding at low concentration, ion transit, or release at high concentration. |
| first_indexed | 2024-03-06T23:29:41Z |
| format | Journal article |
| id | oxford-uuid:6b99adfa-1d0a-40ad-aa02-78011dd0fd18 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:29:41Z |
| publishDate | 2013 |
| publisher | National Academy of Sciences |
| record_format | dspace |
| spelling | oxford-uuid:6b99adfa-1d0a-40ad-aa02-78011dd0fd182022-03-26T19:05:08ZMechanism and kinetics of a sodium-driven bacterial flagellar motorJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:6b99adfa-1d0a-40ad-aa02-78011dd0fd18EnglishSymplectic Elements at OxfordNational Academy of Sciences2013Lo, CSowa, YPilizota, TBerry, RLo, CSowa, YPilizota, TBerry, RThe bacterial flagellar motor is a large rotary molecular machine that propels swimming bacteria, powered by a transmembrane electrochemical potential difference. It consists of an ∼50-nm rotor and up to ∼10 independent stators anchored to the cell wall. We measured torque-speed relationships of single-stator motors under 25 different combinations of electrical and chemical potential. All 25 torque-speed curves had the same concave-down shape as fully energized wild-type motors, and each stator passes at least 37 ± 2 ions per revolution. We used the results to explore the 25-dimensional parameter space of generalized kinetic models for the motor mechanism, finding 830 parameter sets consistent with the data. Analysis of these sets showed that the motor mechanism has a "powerstroke" in either ion binding or transit; ion transit is channel-like rather than carrier-like; and the rate-limiting step in the motor cycle is ion binding at low concentration, ion transit, or release at high concentration. |
| spellingShingle | Lo, C Sowa, Y Pilizota, T Berry, R Lo, C Sowa, Y Pilizota, T Berry, R Mechanism and kinetics of a sodium-driven bacterial flagellar motor |
| title | Mechanism and kinetics of a sodium-driven bacterial flagellar motor |
| title_full | Mechanism and kinetics of a sodium-driven bacterial flagellar motor |
| title_fullStr | Mechanism and kinetics of a sodium-driven bacterial flagellar motor |
| title_full_unstemmed | Mechanism and kinetics of a sodium-driven bacterial flagellar motor |
| title_short | Mechanism and kinetics of a sodium-driven bacterial flagellar motor |
| title_sort | mechanism and kinetics of a sodium driven bacterial flagellar motor |
| work_keys_str_mv | AT loc mechanismandkineticsofasodiumdrivenbacterialflagellarmotor AT soway mechanismandkineticsofasodiumdrivenbacterialflagellarmotor AT pilizotat mechanismandkineticsofasodiumdrivenbacterialflagellarmotor AT berryr mechanismandkineticsofasodiumdrivenbacterialflagellarmotor AT loc mechanismandkineticsofasodiumdrivenbacterialflagellarmotor AT soway mechanismandkineticsofasodiumdrivenbacterialflagellarmotor AT pilizotat mechanismandkineticsofasodiumdrivenbacterialflagellarmotor AT berryr mechanismandkineticsofasodiumdrivenbacterialflagellarmotor |