Applying torque to the Escherichia coli flagellar motor using magnetic tweezers.

ABSTRACT: The bacterial flagellar motor of Escherichia coli is a nanoscale rotary engine essential for bacterial propulsion. Studies on the power output of single motors rely on the measurement of motor torque and rotation under external load. Here, we investigate the use of magnetic tweezers, which in principle allow the application and active control of a calibrated load torque, to study single flagellar motors in Escherichia coli. We manipulate the external load on the motor by adjusting the magnetic field experienced by a magnetic bead linked to the motor, and we probe the motor's response. A simple model describes the average motor speed over the entire range of applied fields. We extract the motor torque at stall and find it to be similar to the motor torque at drag-limited speed. In addition,

SUBMITTER: van Oene MM 

PROVIDER: S-EPMC5339722 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature