Angular measurements of the dynein ring reveal a stepping mechanism dependent on a flexible stalk.

ABSTRACT: The force-generating mechanism of dynein differs from the force-generating mechanisms of other cytoskeletal motors. To examine the structural dynamics of dynein's stepping mechanism in real time, we used polarized total internal reflection fluorescence microscopy with nanometer accuracy localization to track the orientation and position of single motors. By measuring the polarized emission of individual quantum nanorods coupled to the dynein ring, we determined the angular position of the ring and found that it rotates relative to the microtubule (MT) while walking. Surprisingly, the observed rotations were small, averaging only 8.3°, and were only weakly correlated with steps. Measurements at two independent labeling positions on opposite sides of the ring showed similar small rotations.

SUBMITTER: Lippert LG 

PROVIDER: S-EPMC5468668 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature