Temperature dependences of torque generation and membrane voltage in the bacterial flagellar motor.

ABSTRACT: In their natural habitats bacteria are frequently exposed to sudden changes in temperature that have been shown to affect their swimming. With our believed to be new methods of rapid temperature control for single-molecule microscopy, we measured here the thermal response of the Na(+)-driven chimeric motor expressed in Escherichia coli cells. Motor torque at low load (0.35 μm bead) increased linearly with temperature, twofold between 15°C and 40°C, and torque at high load (1.0 μm bead) was independent of temperature, as reported for the H(+)-driven motor. Single cell membrane voltages were measured by fluorescence imaging and these were almost constant (∼120 mV) over the same temperature range. When the motor was heated above 40°C for 1-2 min the torque at high load dropped reversibly, rec

SUBMITTER: Inoue Y 

PROVIDER: S-EPMC3882455 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature